https://DevOpsCloud.io -- Cloud Monk Losang Jinpa, Ph.D., MCSE/MCT, GitOps DevOps Engineer

Return to JavaScript Standard Library, Standard Library, JavaScript, JavaScript Libraries, Full-Stack Web Development, Full-Stack Developer, core-js Glossary, core-js Topics

core-js

Core-js is a widely utilized JavaScript library that serves as a modular standard library, providing polyfills for many features of ECMAScript that are missing in older browsers. This library is especially valuable for developers who need to ensure their web applications function seamlessly across different browsing environments. Core-js offers a robust set of features including polyfills for promises, symbols, collections, iterators, typed arrays, and various other ECMAScript proposals that have not been universally adopted by all browsers.

Core-js was created by Denis Pushkarev, also known as zloirock, and was first introduced in the year 2014. The project was developed to aid in the compatibility of JavaScript codes across different browser versions by implementing polyfills that emulate missing functionalities in older browsers. As a result, developers can write modern JavaScript code without having to worry about the support of these features in legacy environments. This library has become a fundamental tool for web development, facilitating the use of the latest JavaScript standards even in browsers that are not up to date with the latest ECMAScript specifications.

Core-js is a vital JavaScript library designed to ensure web applications are compatible across various browsers by providing polyfills for ECMAScript features that may be lacking in older environments. It acts as a bridge allowing developers to utilize modern JavaScript features without worrying about browser compatibility issues. This library covers a wide range of JavaScript functionalities, from basic language features to complex constructs like promises and iterators.

The library was developed by Denis Pushkarev, also known as zloirock, who launched Core-js in 2014. His vision was to create a comprehensive tool that would allow developers to leverage the latest ECMAScript standards effortlessly across all browsers, regardless of their native support for these standards. Denis Pushkarev continues to actively maintain and update the library, ensuring it remains relevant as new ECMAScript proposals become standardized.

Core-js provides a plethora of features essential for modern web development. These include polyfills for ECMAScript 2015 (also known as ES6), ECMAScript 2016 (also known as ES7), and features from later versions up to the latest drafts of ECMAScript. By including Core-js, developers can use features like symbols, sets, maps, and typed arrays in environments that do not yet support them natively.

Integrating Core-js into a project is straightforward. Developers typically include it at the base of their JavaScript code to ensure all subsequent code can utilize the polyfills. It is compatible with Node.js and can be included in web projects using bundlers like Webpack or Rollup. The modular nature of Core-js allows for selective inclusion of polyfills, which helps in keeping the bundle sizes minimal by only including the features needed for a particular project.

A key aspect of Core-js is its ability to polyfill newer ECMAScript features back to ECMAScript 5, enabling functionalities that are otherwise unsupported in older browsers like Internet Explorer. This backward compatibility is crucial for maintaining accessibility and functionality across diverse user bases, especially in corporate environments where older browsers are still in use.

Core-js has significantly impacted web development by reducing the time and effort developers spend on ensuring cross-browser compatibility. It supports the progressive enhancement strategy in web design, where applications are built for the lowest level of user capability but can enhance their operation with more advanced browser features when available.

Core-js is regularly updated to include polyfills for the latest ECMAScript features as they move through the proposal stages and become part of the language standard. This ongoing maintenance helps developers stay ahead of the curve by allowing them to adopt new features shortly after they are proposed. Denis Pushkarev’s commitment to the project ensures it is one of the most up-to-date polyfill libraries available.

The development of Core-js is supported by a community of developers who contribute to its growth through code contributions, bug reports, and feature requests. This community involvement helps in refining the library and extending its capabilities to cover more features and ensure greater compatibility.

While Core-js provides extensive support for many features, it is not without its limitations. The library can increase the size of web application bundles significantly, particularly if many polyfills are used indiscriminately. Developers need to balance the need for compatibility with the performance implications of adding extra JavaScript code to their projects.

As ECMAScript continues to evolve, Core-js will also need to adapt by incorporating new standards and features. The future of Core-js is likely to involve more intelligent polyfill mechanisms that can more accurately detect and load only the necessary features based on the user’s browser capabilities, potentially integrating with dynamic import systems.

Many popular frameworks and libraries, including Babel, use Core-js as a base for their polyfill strategies. For instance, when a developer uses Babel to transpile modern JavaScript code to be compatible with older browsers, Babel includes relevant polyfills from Core-js based on the targeted browser environments specified in the project's configuration.

Core-js is well-documented, with extensive resources available online to help developers understand and implement the library effectively. The documentation covers installation, usage examples, and a comprehensive list of features that the library supports. This makes it accessible to both novice

and experienced developers.

Core-js stands out as an essential tool in the modern web developer’s toolkit, bridging the gap between the latest JavaScript developments and the diverse landscape of user browsers. Its ability to enable future-proofing of web applications while maintaining broad compatibility has made it a staple in the industry.

core-js Alternatives - Alternatives to core-js

While Core-js is a popular choice for providing polyfills in web development, there are several alternatives that developers might consider based on their specific needs or constraints. These alternatives also offer polyfills for various ECMAScript features, but they may differ in terms of scope, performance, and the specific methods they use to implement the functionalities.

One prominent alternative is Babel-polyfill, which integrates seamlessly with Babel, a JavaScript compiler commonly used to convert modern JavaScript into backward-compatible versions for older browsers. Unlike Core-js, which can be used independently, Babel-polyfill is typically used in conjunction with Babel's transpilation processes. This integration allows it to provide more targeted polyfills based on the specific features that are being transpiled by Babel.

Polyfill.io is a service that takes a different approach by dynamically serving only the necessary polyfills based on the browser making the request. This feature is particularly useful for reducing the size of the JavaScript bundle, as it ensures that browsers only load the polyfills they need. This can significantly improve page load times and overall performance, especially in modern browsers that may require fewer polyfills.

The ES-Shims project provides a collection of shims and polyfills for a broad range of ECMAScript features. It is particularly comprehensive, covering more speculative or less commonly used features that might not be included in other libraries. ES-Shims can be a good choice for developers who need to ensure compatibility for specific or advanced ECMAScript features not fully supported by other polyfill libraries.

Modernizr is another tool that developers use for browser feature detection rather than directly providing polyfills. It allows developers to add classes to the HTML document based on whether certain features are supported in the browser or not. From there, developers can decide to load specific polyfills or alternative styles/scripts as needed. This method is highly customizable and enables developers to build a more tailored experience based on the user's browser capabilities.

core-js Command-Line Interface - core-js CLI:

Create a list of the top 40 core-js CLI commands with no description or definitions. Sort by most common. Include NO description or definitions. Put double square brackets around each topic. Don't number them, separate each topic with only a comma and 1 space.

core-js Command-Line Interface - core-js CLI:

Summarize this topic in 15 paragraphs with descriptions and examples for the most commonly used CLI commands. Make the Wikipedia or other references URLs as raw URLs. Put a section heading for each paragraph. Section headings must start and end with 2 equals signs. Do not put double square brackets around words in section headings. You MUST put double square brackets around ALL computer buzzwords, product names, or jargon or technical words.

core-js Best Practices:

Core-js is a JavaScript library that provides polyfills for the latest ECMAScript features, allowing developers to use these features in environments where they are not natively supported. It is essential for maintaining compatibility across various browsers, especially older ones, ensuring that users have a consistent experience regardless of their browser's capabilities.

When using Core-js, it is crucial to import only the specific polyfills you need. This approach, known as modular imports, helps reduce the overall size of your JavaScript bundles. Core-js is designed to be modular, allowing you to include individual features rather than the entire library, which optimizes both loading times and performance.

Integrating Core-js with build tools like Webpack or Rollup is a standard practice. These tools can automatically include the necessary polyfills as part of the build process. Configuration options within these tools allow developers to specify which environments they are targeting, thus tailoring the polyfills to only those needed for compatibility.

Babel is often used alongside Core-js for transpiling modern JavaScript code into a form that can be understood by older browsers. When setting up Babel, you can specify which version of Core-js to use, ensuring that the polyfills are aligned with the ECMAScript features you are using in your project.

Keeping the Core-js configuration up to date is crucial. This includes regularly updating the version of Core-js as part of your project dependencies to benefit from the latest polyfills and bug fixes. Failure to update can lead to compatibility issues or missing features, which could degrade the user experience.

Thorough browser testing is essential when using Core-js. Developers should test their applications across all supported browsers to ensure that polyfills are functioning correctly. This process helps identify any gaps in the polyfill coverage or issues with specific browser versions.

Understanding the scope and limitations of each polyfill in Core-js is important for effective use. Some polyfills may have limitations in how accurately they mimic native implementations, which could affect application behavior. Developers need to be aware of these limitations to avoid unexpected bugs.

For projects that need to support legacy browsers, such as older versions of Internet Explorer, Core-js is particularly valuable. However, it's important to balance the need for these polyfills with the performance implications of loading unnecessary code in modern browsers that do not need them.

Performance optimization is critical when using polyfills. Developers should measure the impact of adding Core-js on page load times and overall application performance. Techniques such as lazy loading of polyfills based on feature detection can help mitigate performance penalties.

Utilizing the documentation provided by Core-js and participating in community discussions can greatly enhance a developer's ability to use the library effectively. The Core-js GitHub page and other online forums provide valuable resources for troubleshooting and learning best practices.

Developers must consider the security implications of using polyfills. Since Core-js modifies native JavaScript environments, it's important to ensure that these changes do not introduce security vulnerabilities, particularly when dealing with sensitive data.

Contributing to the development of Core-js can benefit the wider community. By submitting bug reports, feature requests, or patches, developers can help improve the library and ensure it continues to meet the needs of a diverse developer community.

Organizations should consider training their development teams on best practices for using Core-js. Sharing knowledge about how to effectively integrate and leverage polyfills can lead to more robust and compatible web applications.

Staying informed about future trends in ECMAScript and Core-js is crucial. As the JavaScript landscape evolves, Core-js will continue to adapt, adding new features and improving existing ones to better serve the development community.

In conclusion, using Core-js effectively requires understanding its capabilities and limitations, integrating it properly with other tools, maintaining an up-to-date configuration, optimizing for performance, and engaging with the community. By following these best practices, developers can leverage Core-js to build robust, compatible, and efficient web applications.

core-js Anti-Patterns:

Using Core-js effectively requires understanding not just what to do but also what to avoid. Common anti-patterns can undermine the benefits of this powerful polyfill library. Recognizing these pitfalls is crucial for maintaining optimal performance and compatibility in web development projects.

One of the most frequent anti-patterns is over-polyfilling, where developers include more polyfills than necessary. This can lead to bloated JavaScript bundles, negatively impacting the load times and performance of web applications. Developers should carefully select only the polyfills that are necessary for the browsers they are targeting, rather than including the entire Core-js library by default.

Improper configuration of Core-js with Babel can lead to significant issues. A common mistake is not specifying the correct version of Core-js or misaligning it with the project's ECMAScript feature usage, resulting in either missing polyfills or redundant code. Ensuring that Babel's configuration is carefully aligned with the Core-js version can prevent these issues.

Another anti-pattern is ignoring browser-specific needs by using a one-size-fits-all approach to polyfills. Different browsers have different levels of support for ECMAScript features, and using the same set of polyfills for all can lead to unnecessary code execution and wasted resources. It's more efficient to tailor polyfill inclusion based on the specific requirements of each browser version.

Failing to thoroughly test web applications across all targeted browsers is a critical oversight. This can lead to situations where certain features do not function as expected due to inadequate or incorrect polyfill coverage. Regular and comprehensive testing ensures that polyfills are effectively supporting the application as intended.

Not performing performance benchmarking after integrating Core-js is a significant anti-pattern. Without benchmarking, it's challenging to understand the impact of polyfills on the application's performance. Developers should regularly measure performance to ensure that the inclusion of Core-js does not adversely affect user experience.

Lastly, a common mistake is to continue polyfilling features that modern browsers already support natively. This not only wastes resources but also potentially conflicts with native implementations, which are typically more efficient. Developers should periodically review and update their polyfill strategy to exclude features that have become widely supported in updated browser versions.

core-js Security

Security is a paramount concern when using any third-party JavaScript library, including Core-js. Since Core-js modifies the native environment of ECMAScript to implement its polyfills, it's essential to understand the security implications of these modifications. Ensuring that Core-js does not introduce vulnerabilities is crucial for maintaining the overall security of web applications.

Polyfills can potentially introduce vulnerabilities if they are not implemented correctly. Since Core-js aims to mimic native ECMAScript behaviors, any discrepancies or flaws in the implementation could be exploited by attackers. It is vital to ensure that the polyfills used do not open up security holes, particularly in areas like object prototypes or global environment modifications.

One of the key security practices with Core-js is to keep the library updated. Each new release can contain patches for security vulnerabilities that were discovered in earlier versions. Regular updates ensure that security patches and improvements are applied, reducing the risk of exposing web applications to exploits through outdated code.

When integrating Core-js with Babel, it's important to configure both tools securely. Misconfigurations can lead to unintended global exposures or conflicts that might be exploited. Ensuring that the setup only includes necessary polyfills and follows security best practices can help mitigate such risks.

Since Core-js is a third-party library, it's important to review its code and understand its functionality before integrating it into your projects. Awareness of what the library does, especially how it interacts with the global scope and native objects, is crucial for maintaining security. Trusting the library without understanding its implications can lead to security lapses.

Implementing thorough testing procedures to check for security flaws in the areas affected by Core-js polyfills is essential. Security testing should be a part of the development cycle, ensuring that the introduction of polyfills does not inadvertently compromise application security. This includes both static analysis and dynamic testing methods.

Core-js sometimes provides polyfills for deprecated or soon-to-be-deprecated ECMAScript features. Using deprecated features can be risky as they may not receive security updates or support. Developers should be cautious about using polyfills for deprecated features and consider the security implications of maintaining such code.

Finally, educating developers on secure coding practices related to the use of Core-js and polyfills is crucial. Understanding the best practices for secure use of third-party libraries, regular updates, and secure coding can help mitigate potential security risks associated with using Core-js in web development projects.

core-js Programming Languages:

Discuss which programming languages are supported. Discuss which programming languages are most commonly used. Summarize this topic in 4 paragraphs. Make the Wikipedia or other references URLs as raw URLs. Put a section heading for each paragraph. Section headings must start and end with 2 equals signs. Do not put double square brackets around words in section headings. You MUST put double square brackets around ALL computer buzzwords, product names, or jargon or technical words.

core-js and Unit Testing:

Core-js is a library that provides polyfills for JavaScript, ensuring that features from the latest ECMAScript standards can be used in environments that do not natively support them. While Core-js itself is not a unit testing framework, it plays a crucial role in testing environments by allowing developers to test JavaScript code that uses newer language features across multiple browser versions. This capability is especially important in unit testing scenarios where consistent behavior across environments is necessary for accurate testing outcomes.

When setting up a unit testing environment for a project that uses Core-js, developers typically integrate it with a testing framework like Jest, Mocha, or Jasmine. These frameworks handle the execution of tests and provide useful features such as mocks, spies, and assertion libraries. Core-js is included in the project's setup files to ensure that all tests run with the necessary ECMAScript polyfills in place, allowing tests to run smoothly even in older execution environments:

```javascript // Example of integrating Core-js with Jest in jest.config.js module.exports = {

   setupFiles: ['core-js']

// Using an ES2020 feature in a test test('array.includes works correctly with NaN', () ⇒ {

   expect([NaN].includes(NaN)).toBe(true);

This configuration ensures that features like `Array.prototype.includes` are available during tests, replicating a fully ES2020-compliant environment.

Testing in environments enhanced by Core-js can introduce specific challenges. One such issue is ensuring that the polyfills do not alter the behavior of the application in ways that would not be representative of an environment where native support for the features exists. It is also crucial to make sure that Core-js does not interfere with the mocking or stubbing of built-in JavaScript objects, which can lead to brittle tests that fail in real-world scenarios:

```javascript // Potential pitfall when testing with polyfills test('String.prototype.replaceAll is not incorrectly mocked', () ⇒ {

   const originalReplaceAll = String.prototype.replaceAll;
   String.prototype.replaceAll = () => 'mocked';
   expect('real'.replaceAll('re', 'fa')).toBe('mocked'); // This test may fail unexpectedly in native environments
   String.prototype.replaceAll = originalReplaceAll;

Developers need to carefully design their tests to account for the presence of polyfills, ensuring that they do not inadvertently test the polyfill rather than the actual application logic.

To effectively use Core-js in unit testing scenarios, it is essential to maintain clear separation between tests that check polyfilled functionality and those that test application-specific logic. Utilizing conditional test patterns based on feature detection can also help differentiate between environments that require polyfills and those that do not:

```javascript // Conditional testing based on feature availability if (!String.prototype.replaceAll) {

   test('replaceAll polyfill behaves as expected', () => {
       expect('test'.replaceAll('t', 'b')).toBe('besb');
   });

By carefully managing the use of Core-js in unit tests and ensuring that tests are aware of the environment, developers can maximize the reliability and relevance of their test suites across various JavaScript execution contexts.

core-js and Performance:

Core-js is widely used to provide polyfills for newer ECMAScript features in environments that do not support them natively. While it is an invaluable tool for achieving cross-browser compatibility, it is important to consider its impact on performance. Integrating Core-js can potentially increase the execution time and resource consumption of web applications, especially if a large number of polyfills are loaded, regardless of whether they are used by the client's browser or not. Developers need to balance the benefits of using Core-js with the possible drawbacks related to increased page load times and execution overhead.

One effective way to mitigate performance issues when using Core-js is to selectively load polyfills based on the features that are actually needed by the application and supported by the user’s browser. This approach minimizes the unnecessary code sent to the client, reducing load times and parsing overhead. For example, before loading a polyfill, a check can be performed to see if the browser already supports the feature:

```javascript if (!Array.prototype.flat) {

   require('core-js/features/array/flat');

This code checks if the `Array.prototype.flat` method is missing, and only loads the polyfill if it is not natively supported, thereby ensuring that only necessary polyfills are loaded.

The indiscriminate inclusion of Core-js can significantly increase the size of JavaScript bundles, affecting the application’s load time. Moreover, since polyfills simulate native features using JavaScript, they can be slower than their native counterparts. It's important to analyze the performance implications of each polyfill:

```javascript // Measuring performance of a polyfilled feature console.time('flat'); [1, [2, [3, [4]], 5]].flat(Infinity); console.timeEnd('flat'); // Outputs the time it takes to flatten an array ```

This example measures the time it takes to flatten a nested array using the `flat()` method provided by Core-js. Monitoring such metrics helps in understanding the cost of using polyfills in terms of execution speed.

To optimize the use of Core-js and mitigate its impact on performance, it is advisable to integrate only the necessary modules. Utilizing tools like Webpack or Rollup allows developers to include polyfills only for the specific features used by the application, which are not natively supported by the target browsers. Additionally, developers should regularly review the polyfills included in their projects as browser technologies evolve, potentially making some polyfills obsolete:

```javascript // Using Webpack to only include necessary polyfills module.exports = {

   entry: 'index.js',
   module: {
       rules: [
           {
               test: /\.js$/,
               use: {
                   loader: 'babel-loader',
                   options: {
                       presets: [
                           ['@babel/preset-env', {
                               useBuiltIns: 'usage',
                               corejs: 3,
                               targets: "> 0.25%, not dead"
                           }]
                       ]
                   }
               }
           }
       ]
   }

This configuration uses Babel along with Webpack to automatically determine and include polyfills needed for the browsers specified in the `targets` option. This method ensures that only the necessary parts of Core-js are bundled, enhancing performance.

core-js and WebAssembly:

Discuss how WebAssembly / Wasm is supported by core-js. Give code examples. Summarize this topic in 4 paragraphs. Make the Wikipedia or other references URLs as raw URLs. Put a section heading for each paragraph. Section headings must start and end with 2 equals signs. Do not put double square brackets around words in section headings. You MUST put double square brackets around ALL computer buzzwords, product names, or jargon or technical words.

core-js Automation with Python

Summarize this topic in 3 paragraphs. Give 3 code examples. Make the Wikipedia or other references URLs as raw URLs. Put a section heading for each paragraph. Section headings must start and end with 2 equals signs. Do not put double square brackets around words in section headings. You MUST put double square brackets around ALL computer buzzwords, product names, or jargon or technical words.

core-js Automation with Java

Summarize this topic in 3 paragraphs. Give 3 code examples. Make the Wikipedia or other references URLs as raw URLs. Put a section heading for each paragraph. Section headings must start and end with 2 equals signs. Do not put double square brackets around words in section headings. You MUST put double square brackets around ALL computer buzzwords, product names, or jargon or technical words.

core-js Automation with JavaScript

Summarize this topic in 3 paragraphs. Give 3 code examples. Make the Wikipedia or other references URLs as raw URLs. Put a section heading for each paragraph. Section headings must start and end with 2 equals signs. Do not put double square brackets around words in section headings. You MUST put double square brackets around ALL computer buzzwords, product names, or jargon or technical words.

core-js Automation with Golang

Summarize this topic in 3 paragraphs. Give 3 code examples. Make the Wikipedia or other references URLs as raw URLs. Put a section heading for each paragraph. Section headings must start and end with 2 equals signs. Do not put double square brackets around words in section headings. You MUST put double square brackets around ALL computer buzzwords, product names, or jargon or technical words.

core-js Automation with Rust

Summarize this topic in 3 paragraphs. Give 3 code examples. Make the Wikipedia or other references URLs as raw URLs. Put a section heading for each paragraph. Section headings must start and end with 2 equals signs. Do not put double square brackets around words in section headings. You MUST put double square brackets around ALL computer buzzwords, product names, or jargon or technical words.

core-js Glossary:

ECMAScript: A standardized scripting language used to implement the core functionality of JavaScript, providing the specifications that JavaScript engines should follow.

Polyfill: Code that implements features in older browsers that do not support those features natively, allowing developers to use modern ECMAScript features in environments that are otherwise unsupported.

Babel: A JavaScript compiler tool that transforms modern JavaScript code into backward-compatible versions for older browsers, often used in conjunction with polyfills like Core-js.

Shim: A library that brings a new API to an older environment, using only the means of that environment.

Transpiler: A type of compiler that takes the source code written in one language and transforms it into equivalent code in another language, typically used for converting newer ECMAScript syntax into older syntax that can be executed by legacy browsers.

Module: In JavaScript, a file or script that encapsulates code and functionality, which can be imported and used in other JavaScript files, allowing for better code organization and reusability.

Webpack: A static module bundler for modern JavaScript applications, which compiles modules with dependencies to generate static assets representing those modules.

Polyfill.io: A service that automatically provides only the necessary polyfills based on the browser's user-agent string, optimizing load times by loading only required code.

Node.js: An open-source, cross-platform, back-end JavaScript runtime environment that runs on the V8 engine and executes JavaScript code outside a web browser.

ECMAScript 2015 (also known as ES6): A significant update to the ECMAScript standard introduced in 2015 that includes new syntax and features such as classes, modules, and arrow functions, greatly enhancing the capability of JavaScript.

Rollup: A JavaScript module bundler that compiles small pieces of code into something larger and more complex, such as a library or application, focusing on efficiency and speed.

Legacy Browser: An older version of a web browser that does not support newer web standards or technologies, often requiring additional scripts like polyfills to emulate missing features.

Global Environment: In JavaScript, the global environment is the context that contains all the globally accessible objects, functions, and variables.

Feature Detection: A technique used in web development to determine if certain web features are supported by the client's browser, allowing developers to conditionally load polyfills or alternative implementations.

ECMAScript Proposals: Suggestions for new features or improvements to the ECMAScript standard, which undergo a formal process of review and iteration before possibly being accepted and integrated into the standard.

TypeScript: A superset of JavaScript developed by Microsoft, which adds static types to the language. It is designed to develop large applications and transpiles to JavaScript.

Promise: An object representing the eventual completion or failure of an asynchronous operation and its resulting value, used extensively in modern JavaScript for managing asynchronous operations.

Symbol: A unique and immutable primitive value that can be used as the key of an object property, introduced in ECMAScript 2015 to help prevent name clashes between properties.

Iterator: An object that facilitates the iteration over a collection, such as an array or a string, by implementing a specific interface that returns a sequence of values.

V8: An open-source JavaScript engine developed by Google, used in Google Chrome and Node.js. It is known for its high performance and compliance with the ECMAScript standard.

Arrow Function: A concise syntax for writing function expressions in JavaScript that does not have its own `this`, `arguments`, `super`, or `new.target` bindings, which allows it to inherit them from the enclosing lexical context.

Class: A template for creating objects in JavaScript that encapsulates data and functions that operate on the data, introduced in ECMAScript 2015 to provide a more object-oriented approach to JavaScript programming.

Set: A collection of unique values in JavaScript, where each value must be unique and is a part of the standard built-in object set provided by ECMAScript 2015.

Map: An ordered collection of key-value pairs in JavaScript, where keys can be of any data type and are unique within the map, offering better performance for inserting and retrieving values compared to plain objects.

Typed Arrays: An array-like view of binary data introduced in ECMAScript 2015, which provides a mechanism for accessing raw binary data much more efficiently and with less overhead than traditional JavaScript arrays.

Async/Await: Syntactic sugar built on top of promises in JavaScript that makes asynchronous code easier to write and read. Introduced in ECMAScript 2017, it allows developers to handle asynchronous operations in a more synchronous-like fashion.

Spread Operator: A syntax in JavaScript that allows an iterable such as an array expression or string to be expanded in places where zero or more arguments (for function calls) or elements (for array literals) are expected.

Proxy: An object that wraps another object and intercepts operations, like reading/writing properties and others, allowing for custom behavior when these operations are performed on the proxy.

Reflect: A built-in object that provides methods for interceptable JavaScript operations, such as constructing an object, getting and setting properties. It is closely related to the Proxy mechanism and facilitates its handling of default behaviors.

Generator: A function that can stop midway and later resume its execution. Generators are useful for managing asynchronous flows and are part of the ECMAScript 2015 standard, providing an easier way to implement iterable behaviors.

Snippet from Wikipedia: Polyfill (programming)

In software development, a polyfill is code that implements a new standard feature of a deployment environment within an old version of that environment that does not natively support the feature. Most often, it refers to JavaScript code that implements an HTML5 or CSS web standard, either an established standard (supported by some browsers) on older browsers, or a proposed standard (not supported by any browsers) on existing browsers. Polyfills are also used in PHP and Python.

Polyfills allow web developers to use an API regardless of whether or not it is supported by a browser, and usually with minimal overhead. Typically they first check if a browser supports an API, and use it if available, otherwise using their own implementation. Polyfills themselves use other, more supported features, and thus different polyfills may be needed for different browsers. The term is also used as a verb: polyfilling is providing a polyfill for a feature.

Creative Commons Attribution-Share Alike 4.0

Research:

• core-js on DuckDuckGo
• core-js on Google.com
• core-js on O'Reilly
• core-js on GitHub

• core-js on javatpoint.com
• core-js on w3schools.com
• core-js on tutorialspoint.com
• core-js on FreeCodeCamp.org

• core-js on AWS Docs
• core-js on Kubernetes.io
• core-js on docs.microsoft.com
• core-js on GCP Docs
• core-js on IBM Docs
• core-js on Red Hat Docs
• core-js on Oracle Docs

• core-js on YouTube
• core-js on Reddit
• core-js on scholar.google.com
• core-js on Stackoverflow
• core-js on Quora
• core-js on Dzone
• core-js on Hacker Noon
• core-js on InfoQ.com

Fair Use Sources:

• core-js for Archive Access for Fair Use Preservation, quoting, paraphrasing, excerpting and/or commenting upon

navbar_core-js

core-js: core-js Glossary, core-js Alternatives, core-js Best Practices, core-js Anti-Patterns, core-js Security, core-js and Programming Languages, core-js Automation with JavaScript, Python and core-js, Java and core-js, JavaScript and core-js, TypeScript and core-js, core-js Alternatives, core-js Bibliography, core-js DevOps - core-js SRE - core-js CI/CD, Cloud Native core-js - core-js Microservices - Serverless core-js, core-js Security - core-js DevSecOps, Functional core-js, core-js Concurrency, Async core-js, core-js and Data Science - core-js and Databases, core-js and Machine Learning, core-js Courses, Awesome core-js, core-js GitHub, core-js Topics

Most Common topics:

. (navbar_core-js – see also navbar_full_stack, navbar_javascript, navbar_node, navbar_software_architecture)

Create a list of the top 30 core-js topics with no description or definitions. Sort by most common. Include NO description or definitions. Put double square brackets around each topic. Don't number them, separate each topic with only a comma and 1 space.

JavaScript Programming Language, JavaScript ECMAScript Standard, JavaScript Variable Declaration, JavaScript let Keyword, JavaScript const Keyword, JavaScript var Keyword, JavaScript Function Declaration, JavaScript Arrow Function, JavaScript Async Function, JavaScript Await Keyword, JavaScript Promise, JavaScript Callback Function, JavaScript JSON (JavaScript Object Notation), JavaScript Object, JavaScript Array, JavaScript String, JavaScript Number, JavaScript Boolean, JavaScript Null, JavaScript Undefined, JavaScript Symbol, JavaScript BigInt, JavaScript Template Literal, JavaScript Destructuring Assignment, JavaScript Spread Operator, JavaScript Rest Parameter, JavaScript Map Object, JavaScript Set Object, JavaScript WeakMap, JavaScript WeakSet, JavaScript Date Object, JavaScript RegExp Object, JavaScript Class Declaration, JavaScript Prototype, JavaScript Inheritance, JavaScript this Keyword, JavaScript new Operator, JavaScript delete Operator, JavaScript instanceof Operator, JavaScript typeof Operator, JavaScript Object.keys, JavaScript Object.values, JavaScript Object.entries, JavaScript Object.assign, JavaScript Object.freeze, JavaScript Object.seal, JavaScript Object.create, JavaScript Object.defineProperty, JavaScript Array.push, JavaScript Array.pop, JavaScript Array.shift, JavaScript Array.unshift, JavaScript Array.slice, JavaScript Array.splice, JavaScript Array.forEach, JavaScript Array.map, JavaScript Array.filter, JavaScript Array.reduce, JavaScript Array.reduceRight, JavaScript Array.some, JavaScript Array.every, JavaScript Array.find, JavaScript Array.findIndex, JavaScript Array.includes, JavaScript Array.indexOf, JavaScript Array.flat, JavaScript Array.flatMap, JavaScript String.length, JavaScript String.charAt, JavaScript String.charCodeAt, JavaScript String.includes, JavaScript String.indexOf, JavaScript String.slice, JavaScript String.substring, JavaScript String.substr, JavaScript String.toUpperCase, JavaScript String.toLowerCase, JavaScript String.trim, JavaScript String.replace, JavaScript String.split, JavaScript String.startsWith, JavaScript String.endsWith, JavaScript Number.parseInt, JavaScript Number.parseFloat, JavaScript Number.isNaN, JavaScript Number.isInteger, JavaScript Math Object, JavaScript Math.random, JavaScript Math.floor, JavaScript Math.ceil, JavaScript Math.round, JavaScript Math.max, JavaScript Math.min, JavaScript Math.abs, JavaScript Math.pow, JavaScript Math.sqrt, JavaScript JSON.stringify, JavaScript JSON.parse, JavaScript Promise.then, JavaScript Promise.catch, JavaScript Promise.finally, JavaScript Promise.resolve, JavaScript Promise.reject, JavaScript Promise.all, JavaScript Promise.race, JavaScript Promise.allSettled, JavaScript Async/Await Syntax, JavaScript console.log, JavaScript console.error, JavaScript console.warn, JavaScript console.info, JavaScript console.table, JavaScript console.debug, JavaScript console.group, JavaScript console.groupEnd, JavaScript console.clear, JavaScript Debugger Keyword, JavaScript Strict Mode, JavaScript Use Strict Directive, JavaScript Module Import, JavaScript Module Export, JavaScript Default Export, JavaScript Named Export, JavaScript import Keyword, JavaScript export Keyword, JavaScript Dynamic Import, JavaScript DOM (Document Object Model), JavaScript document Object, JavaScript window Object, JavaScript navigator Object, JavaScript location Object, JavaScript history Object, JavaScript screen Object, JavaScript fetch API, JavaScript XMLHttpRequest, JavaScript Event Listener, JavaScript addEventListener, JavaScript removeEventListener, JavaScript Event Bubbling, JavaScript Event Capturing, JavaScript Event Propagation, JavaScript MouseEvent, JavaScript KeyboardEvent, JavaScript TouchEvent, JavaScript CustomEvent, JavaScript dispatchEvent, JavaScript classList, JavaScript querySelector, JavaScript querySelectorAll, JavaScript getElementById, JavaScript getElementsByClassName, JavaScript getElementsByTagName, JavaScript createElement, JavaScript createTextNode, JavaScript appendChild, JavaScript removeChild, JavaScript replaceChild, JavaScript innerHTML, JavaScript textContent, JavaScript style Property, JavaScript getComputedStyle, JavaScript Local Storage, JavaScript Session Storage, JavaScript Cookie Handling, JavaScript setTimeout, JavaScript setInterval, JavaScript clearTimeout, JavaScript clearInterval, JavaScript requestAnimationFrame, JavaScript cancelAnimationFrame, JavaScript fetch(url), JavaScript fetch Options, JavaScript fetch Headers, JavaScript fetch Body, JavaScript Promise Chaining, JavaScript async Keyword, JavaScript await Keyword, JavaScript Generators, JavaScript yield Keyword, JavaScript Iterator Protocol, JavaScript Iterable Protocol, JavaScript Symbol.iterator, JavaScript for...of Loop, JavaScript for...in Loop, JavaScript Object Literal, JavaScript Shorthand Property, JavaScript Computed Property Name, JavaScript Arrow Function this Binding, JavaScript Default Parameters, JavaScript Rest Parameters, JavaScript Spread Syntax, JavaScript Destructuring Patterns, JavaScript Object Destructuring, JavaScript Array Destructuring, JavaScript Template Strings, JavaScript Tagged Templates, JavaScript Intl API, JavaScript Intl.NumberFormat, JavaScript Intl.DateTimeFormat, JavaScript Intl.Collator, JavaScript Intl.PluralRules, JavaScript Intl.RelativeTimeFormat, JavaScript Intl.ListFormat, JavaScript Intl.DisplayNames, JavaScript Intl.Locale, JavaScript Weak References, JavaScript WeakRef, JavaScript FinalizationRegistry, JavaScript Symbols, JavaScript Symbol.for, JavaScript Symbol.keyFor, JavaScript Proxy Object, JavaScript Reflect Object, JavaScript Reflect.apply, JavaScript Reflect.construct, JavaScript Reflect.defineProperty, JavaScript Reflect.deleteProperty, JavaScript Reflect.get, JavaScript Reflect.set, JavaScript Reflect.getOwnPropertyDescriptor, JavaScript Reflect.getPrototypeOf, JavaScript Reflect.setPrototypeOf, JavaScript Reflect.has, JavaScript Reflect.ownKeys, JavaScript Proxy Handlers, JavaScript Proxy get Trap, JavaScript Proxy set Trap, JavaScript Proxy has Trap, JavaScript Proxy deleteProperty Trap, JavaScript Proxy defineProperty Trap, JavaScript Proxy getOwnPropertyDescriptor Trap, JavaScript Proxy getPrototypeOf Trap, JavaScript Proxy setPrototypeOf Trap, JavaScript Proxy ownKeys Trap, JavaScript Proxy apply Trap, JavaScript Proxy construct Trap, JavaScript Strict Mode Errors, JavaScript Eval Function, JavaScript Function.prototype.call, JavaScript Function.prototype.apply, JavaScript Function.prototype.bind, JavaScript Object.prototype.toString, JavaScript Object.prototype.hasOwnProperty, JavaScript Object.prototype.isPrototypeOf, JavaScript Object.prototype.propertyIsEnumerable, JavaScript ArrayBuffer, JavaScript TypedArray, JavaScript Uint8Array, JavaScript Uint16Array, JavaScript Uint32Array, JavaScript Int8Array, JavaScript Int16Array, JavaScript Int32Array, JavaScript Float32Array, JavaScript Float64Array, JavaScript BigUint64Array, JavaScript BigInt64Array, JavaScript DataView, JavaScript Blob, JavaScript File API, JavaScript FileReader, JavaScript URL API, JavaScript URLSearchParams, JavaScript FormData, JavaScript WebSocket, JavaScript EventSource, JavaScript BroadcastChannel, JavaScript Worker, JavaScript Service Worker, JavaScript IndexedDB, JavaScript WebGL, JavaScript Canvas API, JavaScript OffscreenCanvas, JavaScript AudioContext, JavaScript VideoContext (Hypothetical), JavaScript Web Audio API, JavaScript MediaDevices, JavaScript MediaStream, JavaScript MediaRecorder, JavaScript WebRTC (Web Real-Time Communication), JavaScript RTCPeerConnection, JavaScript RTCDataChannel, JavaScript RTCSessionDescription, JavaScript RTCIceCandidate, JavaScript History API, JavaScript Push API, JavaScript Notification API, JavaScript Geolocation API, JavaScript Web Storage API, JavaScript Web Animations API, JavaScript ResizeObserver, JavaScript IntersectionObserver, JavaScript MutationObserver, JavaScript Performance API, JavaScript Performance.now, JavaScript Page Visibility API, JavaScript Fullscreen API, JavaScript Screen Orientation API, JavaScript Clipboard API, JavaScript RequestIdleCallback, JavaScript Payment Request API, JavaScript Credential Management API, JavaScript Web Speech API, JavaScript SpeechRecognition, JavaScript SpeechSynthesis, JavaScript Picture-in-Picture API, JavaScript Pointer Events, JavaScript PointerEvent, JavaScript Touch Events, JavaScript Drag and Drop API, JavaScript History.pushState, JavaScript History.replaceState, JavaScript Custom Elements, JavaScript Shadow DOM, JavaScript HTML Templates, JavaScript HTML Imports (Deprecated), JavaScript ES Modules, JavaScript CommonJS Modules, JavaScript AMD (Asynchronous Module Definition), JavaScript UMD (Universal Module Definition), JavaScript Node.js Runtime, JavaScript NPM (Node Package Manager), JavaScript Yarn Package Manager, JavaScript pnpm Package Manager, JavaScript Webpack Bundler, JavaScript Parcel Bundler, JavaScript Rollup Bundler, JavaScript Babel Transpiler, JavaScript ESLint Linter, JavaScript Prettier Formatter, JavaScript Jest Testing, JavaScript Mocha Testing, JavaScript Chai Assertion, JavaScript Jasmine Testing, JavaScript QUnit Testing, JavaScript Karma Test Runner, JavaScript WebDriver, JavaScript Protractor (Deprecated), JavaScript Cypress Testing, JavaScript Puppeteer, JavaScript Playwright, JavaScript Electron Framework, JavaScript NW.js Framework, JavaScript Gulp Task Runner, JavaScript Grunt Task Runner, JavaScript npm run Scripts, JavaScript Yarn Scripts, JavaScript ESLint Config, JavaScript Babel Preset, JavaScript Babel Plugin, JavaScript TypeScript (JavaScript Superset), JavaScript Flow Type Checker, JavaScript JSDoc Comments, JavaScript Closure Compiler, JavaScript Terser Minifier, JavaScript UglifyJS Minifier, JavaScript Web Components, JavaScript LitElement, JavaScript Polymer Library, JavaScript Angular Framework, JavaScript React Library, JavaScript Vue.js Framework, JavaScript Svelte Framework, JavaScript Preact Library, JavaScript Redux State Management, JavaScript MobX State Management, JavaScript RxJS (Reactive Extensions for JavaScript), JavaScript GraphQL Queries, JavaScript Relay Modern, JavaScript Apollo Client, JavaScript jQuery Library, JavaScript Lodash Utility, JavaScript Underscore Utility, JavaScript Moment.js Date Library, JavaScript Day.js Date Library, JavaScript Luxon Date Library, JavaScript D3.js Data Visualization, JavaScript Three.js 3D Graphics, JavaScript Phaser Game Framework, JavaScript PixiJS Rendering, JavaScript Anime.js Animation, JavaScript GSAP Animation, JavaScript Popper.js Tooltip, JavaScript Bootstrap Framework, JavaScript Material UI, JavaScript Tailwind CSS Integration, JavaScript Styled Components, JavaScript Emotion Styling, JavaScript WebAssembly Integration, JavaScript Babel Polyfill, JavaScript Core-js Polyfill, JavaScript fetch Polyfill, JavaScript Promise Polyfill, JavaScript IntersectionObserver Polyfill, JavaScript Polyfill.io Service, JavaScript regeneratorRuntime, JavaScript Zone.js, JavaScript Meteor Framework, JavaScript Next.js Framework, JavaScript Nuxt.js Framework, JavaScript Gatsby Framework, JavaScript Sapper Framework, JavaScript Ember.js Framework, JavaScript Backbone.js Framework, JavaScript Mithril.js Framework, JavaScript Alpine.js, JavaScript Stimulus.js, JavaScript Aurelia Framework, JavaScript Polymer Elements, JavaScript Angular CLI, JavaScript Create React App, JavaScript Vue CLI, JavaScript Nuxt CLI, JavaScript Gatsby CLI, JavaScript Next CLI, JavaScript Angular Ivy Compiler, JavaScript Angular Ahead-of-Time Compilation, JavaScript React Fiber, JavaScript React Hooks, JavaScript React Context API, JavaScript React Suspense, JavaScript React Concurrent Mode, JavaScript Vue Composition API, JavaScript Vuex State Management, JavaScript Quasar Framework, JavaScript Ionic Framework, JavaScript NativeScript, JavaScript React Native, JavaScript Electron IPC, JavaScript Node.js Process, JavaScript Node.js Buffer, JavaScript Node.js Stream, JavaScript Node.js EventEmitter, JavaScript Node.js fs Module, JavaScript Node.js http Module, JavaScript Node.js path Module, JavaScript Node.js os Module, JavaScript Node.js cluster, JavaScript Node.js crypto Module, JavaScript Node.js child_process Module, JavaScript Node.js readline Module, JavaScript Node.js repl Module, JavaScript Node.js vm Module, JavaScript Node.js global Object, JavaScript Node.js require Function, JavaScript Node.js exports Object, JavaScript Node.js __dirname, JavaScript Node.js __filename, JavaScript Type Assertion (TypeScript), JavaScript JIT Compilation, JavaScript Interpreter Execution, JavaScript Just-In-Time Optimization, JavaScript Inline Caches, JavaScript Hidden Classes, JavaScript Deoptimization, JavaScript V8 Engine, JavaScript SpiderMonkey Engine, JavaScript JavaScriptCore Engine, JavaScript Chakra Engine, JavaScript QuickJS Engine, JavaScript Bun Runtime, JavaScript Deno Runtime, JavaScript ESM (ECMAScript Modules), JavaScript CommonJS Require, JavaScript Tree Shaking, JavaScript Code Splitting, JavaScript Dynamic Import Expressions, JavaScript Lazy Loading, JavaScript Prefetching, JavaScript Preloading, JavaScript Service Worker Cache, JavaScript Progressive Web Apps (PWAs), JavaScript Manifest.json, JavaScript Web App Install Banner, JavaScript IndexedDB Transactions, JavaScript IDBKeyRange, JavaScript Streams API, JavaScript ReadableStream, JavaScript WritableStream, JavaScript TransformStream, JavaScript ByteLengthQueuingStrategy, JavaScript CountQueuingStrategy, JavaScript AbortController, JavaScript AbortSignal, JavaScript CanvasRenderingContext2D, JavaScript OffscreenCanvasRenderingContext2D, JavaScript WebGLRenderingContext, JavaScript WebGL2RenderingContext, JavaScript GPU Web API (WebGPU), JavaScript fetch Abort, JavaScript fetch Response, JavaScript fetch Request, JavaScript Headers Object, JavaScript FormData.append, JavaScript URLSearchParams.append, JavaScript location.reload, JavaScript location.replace, JavaScript location.assign, JavaScript location.href, JavaScript history.back, JavaScript history.forward, JavaScript history.go, JavaScript sessionStorage.setItem, JavaScript sessionStorage.getItem, JavaScript localStorage.setItem, JavaScript localStorage.getItem, JavaScript cookieStorage (Hypothetical), JavaScript Notification.requestPermission, JavaScript Notification Constructor, JavaScript PushSubscription, JavaScript PushManager, JavaScript Geolocation.getCurrentPosition, JavaScript Geolocation.watchPosition, JavaScript Performance.mark, JavaScript Performance.measure, JavaScript PerformanceEntry, JavaScript PerformanceObserver, JavaScript ResizeObserver.observe, JavaScript IntersectionObserver.observe, JavaScript MutationObserver.observe, JavaScript MutationRecord, JavaScript High Resolution Time API, JavaScript PaymentRequest, JavaScript PaymentResponse, JavaScript Credential Management, JavaScript Federated Credential, JavaScript Web Speech Recognition, JavaScript Web Speech Synthesis, JavaScript SpeechSynthesisUtterance, JavaScript SpeechSynthesisVoice, JavaScript PictureInPictureWindow, JavaScript RTCPeerConnection.createOffer, JavaScript RTCPeerConnection.createAnswer, JavaScript RTCPeerConnection.setLocalDescription, JavaScript RTCPeerConnection.setRemoteDescription, JavaScript RTCPeerConnection.addIceCandidate, JavaScript RTCIceCandidateInit, JavaScript RTCSessionDescriptionInit, JavaScript RTCDataChannel.send, JavaScript RTCDataChannel.onmessage, JavaScript RTCDataChannel.onopen, JavaScript RTCDataChannel.onclose, JavaScript RTCDataChannel.bufferedAmount, JavaScript MediaDevices.getUserMedia, JavaScript MediaDevices.getDisplayMedia, JavaScript MediaStream.getTracks, JavaScript MediaStream.addTrack, JavaScript MediaRecorder.start, JavaScript MediaRecorder.stop, JavaScript MediaRecorder.ondataavailable, JavaScript Event.preventDefault, JavaScript Event.stopPropagation, JavaScript Event.stopImmediatePropagation, JavaScript Element.classList.add, JavaScript Element.classList.remove, JavaScript Element.classList.toggle, JavaScript Element.classList.contains, JavaScript Element.getBoundingClientRect, JavaScript Element.scrollIntoView, JavaScript document.createEvent, JavaScript document.createAttribute, JavaScript document.createComment, JavaScript document.createDocumentFragment, JavaScript document.importNode, JavaScript document.adoptNode, JavaScript CSSOM Integration, JavaScript CSSStyleDeclaration, JavaScript style.setProperty, JavaScript style.getPropertyValue, JavaScript style.removeProperty, JavaScript matchMedia, JavaScript matchMedia.addListener, JavaScript matchMedia.removeListener, JavaScript CustomEvent.initCustomEvent, JavaScript DOMTokenList, JavaScript DOMParser, JavaScript XMLSerializer, JavaScript FormData.get, JavaScript FormData.set, JavaScript FormData.delete, JavaScript Intl.getCanonicalLocales, JavaScript Intl.NumberFormat.format, JavaScript Intl.DateTimeFormat.format, JavaScript Intl.Collator.compare, JavaScript Intl.PluralRules.select, JavaScript Intl.RelativeTimeFormat.format, JavaScript Intl.ListFormat.format, JavaScript Intl.DisplayNames.of, JavaScript Intl.Locale.maximize, JavaScript WeakRef.deref, JavaScript FinalizationRegistry.register, JavaScript WeakMap.get, JavaScript WeakMap.set, JavaScript WeakMap.delete, JavaScript WeakSet.add, JavaScript WeakSet.delete, JavaScript WeakSet.has, JavaScript Map.get, JavaScript Map.set, JavaScript Map.delete, JavaScript Map.has, JavaScript Set.add, JavaScript Set.delete, JavaScript Set.has, JavaScript DataView.getInt8, JavaScript DataView.getUint8, JavaScript DataView.setInt8, JavaScript DataView.setUint8, JavaScript Uint8Array.buffer, JavaScript Uint8Array.byteLength, JavaScript Int32Array.subarray, JavaScript Float64Array.fill, JavaScript BigInt64Array.set, JavaScript ArrayBuffer.slice, JavaScript CanvasGradient.addColorStop, JavaScript CanvasPattern.setTransform, JavaScript CanvasRenderingContext2D.fillRect, JavaScript CanvasRenderingContext2D.strokeRect, JavaScript CanvasRenderingContext2D.beginPath, JavaScript CanvasRenderingContext2D.arc, JavaScript CanvasRenderingContext2D.fill, JavaScript CanvasRenderingContext2D.stroke, JavaScript WebGLRenderingContext.clear, JavaScript WebGLRenderingContext.drawArrays, JavaScript OffscreenCanvas.convertToBlob, JavaScript AudioContext.createOscillator, JavaScript AudioContext.createGain, JavaScript AudioContext.destination, JavaScript AudioParam.setValueAtTime, JavaScript AudioParam.linearRampToValueAtTime, JavaScript AudioBufferSourceNode.start, JavaScript AudioBufferSourceNode.stop, JavaScript fetch.text, JavaScript fetch.json, JavaScript fetch.blob, JavaScript fetch.formData, JavaScript fetch.arrayBuffer, JavaScript Request.cache, JavaScript Request.credentials, JavaScript Request.headers, JavaScript Request.redirect, JavaScript Request.url, JavaScript Response.ok, JavaScript Response.status, JavaScript Response.statusText, JavaScript Response.headers, JavaScript Response.body, JavaScript Headers.append, JavaScript Headers.delete, JavaScript Headers.get, JavaScript Headers.has, JavaScript Headers.set, JavaScript URL.href, JavaScript URL.searchParams, JavaScript URLSearchParams.get, JavaScript URLSearchParams.set, JavaScript URLSearchParams.delete, JavaScript URLSearchParams.has, JavaScript FormData.values, JavaScript Node.js CommonJS require, JavaScript Node.js ESM import, JavaScript Web Storage localStorage, JavaScript Web Storage sessionStorage

GPT4o:

AbortController, Absolute URLs, Abstract Equality Comparison, Abstract Syntax Tree, Accessor Properties, ActiveXObject, AddEventListener Method, AJAX Calls, AJAX Polling, Alert Dialogs, Alignment of Elements, All Settled Method in Promises, Animation Frames, Anonymous Functions, API Fetching, Application Cache, Arguments Object, Arrow Functions, Art Direction in Web Design, Asynchronous Iterators, Asynchronous Programming, Async Functions, Attribute Nodes, AudioContext API, Augmented Reality in Web, Authentication Tokens, Automatic Semicolon Insertion, Autoplay Attribute, Await Expression, Backbone of JavaScript Applications, Background Scripts, Backwards Compatibility in JavaScript, Base64 Encoding, Beforeunload Event, Best Practices in JavaScript, Binary Data Handling, Binary Heap in JavaScript, Binding of Functions, Blob Objects, Block-Level Scope, Boolean Objects, Bounding Client Rect, Box Model in CSS, Break and Continue Statements, Broadcast Channels, Browser Compatibility, Browser Event Model, Browser Object Model, Buffer Objects, Built-in Objects, Button Elements, Cache API, Callback Functions, Call Method, Canvas API, Caret Position, Cascading Style Sheets Integration, Case Sensitivity in JavaScript, Change Detection, Character Encoding, Child Nodes, Class Declarations, Class Expressions, Client-Side Rendering, Clipboard API, Closures in JavaScript, Coding Conventions, Collection Objects, Color Depth Detection, Comma Operator, Comparison Operators, Compatibility Mode, Computed Properties, Conditional Comments, Conditional Operator, Console Object, Constructor Functions, Content Security Policy, Context Menu Events, Control Flow in JavaScript, Cookies Management, Copy Event, Cordova Integration, CORS (Cross-Origin Resource Sharing), Create Document Fragment, Crypto API, CSS Object Model, Custom Elements, Custom Events, Data Attributes, Data Binding in JavaScript, Data Types in JavaScript, Data URLs, Date and Time Functions, Debugger Statements, Debugging JavaScript Code, Decimal Numbers, Default Parameters, Deferred Scripts, Delay Function Execution, Delete Operator, Destructuring Assignment, Device Orientation Events, Dialog Element, Difference Between Var, Let, and Const, Digital Certificates in Web, Dimension Properties, Direction Property in CSS, Directive Prologue, Disable Right-Click, Discouraged Practices, DispatchEvent Method, Display Property in CSS, Document Base URL, Document Fragment, Document Object Model (DOM), Document Type Declaration, Doctype in HTML5, Do...While Loop, Drag and Drop API, Dynamic Imports, Dynamic Typing, E4X (ECMAScript for XML), ECMAScript Language Specification, ECMAScript Modules, Edit Distance Algorithm, Element Interface, Element Sizing, Element Traversal, Ember.js Integration, Empty Statements, EncodeURI Function, Encryption in Web Applications, Endless Scrolling Techniques, Engine Differences, Enhanced Object Literals, Enums in JavaScript, Environment Records, Error Handling in JavaScript, Error Objects, Escape Sequences, Eval Function, Event Bubbling, Event Capturing, Event Delegation, Event Handlers, Event Loop in JavaScript, Event Propagation, Event Queue, Event Source Interface, Event Target Interface, Exception Handling, Exec Command, Exponential Operator, Export Statements, Expressions in JavaScript, Extended Object Properties, Extensible Markup Language (XML), Fetch API, Fieldsets in Forms, File API, FileReader Object, Filter Method in Arrays, FinalizationRegistry, Find Method in Arrays, First-Class Functions, Floating Point Arithmetic, Focus Management, Font Loading API, Form Data Validation, Form Submission, FormData Object, Fragment Identifiers, Frame Timing API, Fullscreen API, Function Declarations, Function Expressions, Function Parameters, Function Scope, Functional Programming in JavaScript, Gamepad API, Garbage Collection in JavaScript, Generators in JavaScript, Geolocation API, getComputedStyle Method, getElementById Method, getElementsByClassName Method, getElementsByTagName Method, Global Execution Context, Global Object, Global Scope, GlobalThis Object, Grammar and Types in JavaScript, Grid Layout in CSS, GroupBy Functionality, Hash Tables in JavaScript, History API, Hoisting in JavaScript, Horizontal Rule Element, HTML Canvas Element, HTML Collection, HTML Templates, HTML5 Features, HTTP Requests, HTTP Response Codes, Hyperlinks in HTML, IIFE (Immediately Invoked Function Expression), Image Manipulation in Canvas, Image Preloading Techniques, Import Statements, In Operator, Indexed Collections, IndexedDB API, Infinity Value, Inheritance Patterns, Input Events, Input Validation, Instanceof Operator, Int32Array, Intl Object, Intersection Observer API, Intl.Collator, Intl.DateTimeFormat, Intl.NumberFormat, Invalid Date Object, IsNaN Function, Iteration Protocols, JavaScript Engines, JavaScript Modules, JavaScript Object Notation (JSON), JavaScript Operators, JavaScript Regular Expressions, JavaScript Timers, Joystick Events, JSON Methods, JSON Parse and Stringify, Keydown Event, Keyboard Events, Keyframes in CSS, Label Element in Forms, Language Chains in Testing, let Keyword, Lexical Environment, Lexical Scoping, Light DOM, Line Breaks in Strings, Linear Gradient in CSS, Link Element in HTML, Local Storage, Location Object, Logical AND Operator, Logical NOT Operator, Logical OR Operator, Loops in JavaScript, Map Object in JavaScript, Map Method in Arrays, Math Object, Media Queries in CSS, MediaRecorder API, Memory Leaks in JavaScript, Message Channels, Message Event, Meta Tags in HTML, Method Chaining, MIDI Access, Mime Types, Modals in Web Design, Module Bundlers, Mouse Events, MouseEvent Object, Mutation Observers, Named Function Expressions, Namespace Objects, Native Objects in JavaScript, Navigator Object, Nested Functions, New Operator, Node Interface, NodeList Object, Node.js Integration, Nullish Coalescing Operator, Number Object, Object.create Method, Object.assign Method, Object.defineProperty, Object.entries Method, Object.freeze Method, Object.is Method, Object.keys Method, Object.seal Method, Object.values Method, Observer Pattern in JavaScript, OffscreenCanvas API, Onclick Event, Online and Offline Events, Optional Chaining Operator, Origin Property, Output Encoding, Overflow Property in CSS, Page Visibility API, PageX and PageY Properties, ParentNode Interface, parseFloat Function, parseInt Function, Partial Application, Passive Event Listeners, Path2D Objects, Performance API, Persistent Storage, Pointer Events, Pop Method in Arrays, PopStateEvent, PostMessage Method, Promise.all Method, Promise.any Method, Promise.race Method, Promises in JavaScript, Prompt Dialogs, Prototype Chain, Prototypal Inheritance, Proxy Objects in JavaScript, Push Method in Arrays, Query Selector Methods, QueueMicrotask Function, Radio Buttons in Forms, Random Numbers in JavaScript, Range Input, Readonly Properties, Reference Errors, Reflect API, Regular Expressions, Relative URLs, Rem Units in CSS, Remote Script Execution, Request Animation Frame, Resize Events, Resize Observer API, Rest Parameters, Return Statement, Revealing Module Pattern, Reverse Method in Arrays, Rich Text Editing, Robot Framework Integration, Same-Origin Policy, Screen Orientation API, Script Tag in HTML, Scroll Events, scrollIntoView Method, scrollTo Method, Selection API, Self-Invoking Functions, Semicolons in JavaScript, Server-Sent Events, Service Workers, Set Object in JavaScript, Set Timeout and Set Interval, Shadow DOM, SharedArrayBuffer, Short-Circuit Evaluation, slice Method in Arrays, sort Method in Arrays, Source Maps, Spatial Navigation, splice Method in Arrays, Spread Operator, SQL Injection Prevention, Stack Traces, State Management in Web Apps, Static Methods, Storage Event, String Methods in JavaScript, Strict Mode, Structural Typing, Style Manipulation, Subresource Integrity, switch Statement, Symbol Data Type, Synthetic Events, Tabindex Attribute, Template Literals, Temporal Dead Zone, Text Content Property, Text Direction in CSS, Text Nodes, Throttle Function, throw Statement, Timers in JavaScript, toFixed Method, toString Method, Touch Events, Touch Interface, Traceur Compiler, Transpilers, Tree Shaking, Try...Catch Statement, Type Coercion, Typed Arrays, TypeError Exceptions, typeof Operator, Underscore.js Integration, Unicode in JavaScript, Unicode Normalization, Unary Operators, Undefined Value, Unhandled Rejection, Unit Testing in JavaScript, unshift Method in Arrays, URL API, URLSearchParams, Use Strict Directive, User Timing API, Validation in Forms, ValueOf Method, Variable Hoisting, Variables in JavaScript, Vibration API, Viewport Meta Tag, Visibility Property in CSS, Void Operator, Wake Lock API, WeakMap Object, WeakRef Object, WeakSet Object, Web Animations API, Web Audio API, Web Bluetooth API, Web Components, Web Cryptography API, Web GL, Web Notifications API, Web Real-Time Communications (WebRTC), Web Sockets, Web Speech API, Web Storage API, Web Workers, WebAssembly Integration, Wheel Event, While Loop, Window Object, Window.location Property, Window.postMessage Method, Worker Threads, XML Parsing in JavaScript, XMLHttpRequest Object, XPath Evaluation, XR (Extended Reality) APIs, Yield Keyword, Z-Index Property in CSS

JavaScript: JavaScript Fundamentals, JavaScript Inventor - JavaScript Language Designer: Brendan Eich of Netscape on December 4, 1995; JavaScript DevOps - JavaScript SRE, Cloud Native JavaScript (JavaScript on Kubernetes - JavaScript on AWS - JavaScript on Azure - JavaScript on GCP), JavaScript Microservices, JavaScript Containerization (JavaScript Docker - JavaScript on Docker Hub), Serverless JavaScript, JavaScript Data Science - JavaScript DataOps - JavaScript and Databases (JavaScript ORM), JavaScript ML - JavaScript DL, Functional JavaScript (1. JavaScript Immutability, 2. JavaScript Purity - JavaScript No Side-Effects, 3. JavaScript First-Class Functions - JavaScript Higher-Order Functions, JavaScript Lambdas - JavaScript Anonymous Functions - JavaScript Closures, JavaScript Lazy Evaluation, 4. JavaScript Recursion), Reactive JavaScript), JavaScript Concurrency (WebAssembly - WASM) - JavaScript Parallel Programming - Async JavaScript - JavaScript Async (JavaScript Await, JavaScript Promises, JavaScript Workers - Web Workers, Service Workers, Browser Main Thread), JavaScript Networking, JavaScript Security - JavaScript DevSecOps - JavaScript OAuth, JavaScript Memory Allocation (JavaScript Heap - JavaScript Stack - JavaScript Garbage Collection), JavaScript CI/CD - JavaScript Dependency Management - JavaScript DI - JavaScript IoC - JavaScript Build Pipeline, JavaScript Automation - JavaScript Scripting, JavaScript Package Managers (Cloud Monk's Package Manager Book), JavaScript Modules - JavaScript Packages (NPM and JavaScript, NVM and JavaScript, Yarn Package Manager and JavaScript), JavaScript Installation (JavaScript Windows - Chocolatey JavaScript, JavaScript macOS - Homebrew JavaScript, JavaScript on Linux), JavaScript Configuration, JavaScript Observability (JavaScript Monitoring, JavaScript Performance - JavaScript Logging), JavaScript Language Spec - JavaScript RFCs - JavaScript Roadmap, JavaScript Keywords, JavaScript Operators, JavaScript Functions, JavaScript Built-In Data Types, JavaScript Data Structures - JavaScript Algorithms, JavaScript Syntax, JavaScript OOP (1. JavaScript Encapsulation - 2. JavaScript Inheritance - 3. JavaScript Polymorphism - 4. JavaScript Abstraction), JavaScript Design Patterns - JavaScript Best Practices - JavaScript Style Guide - Clean JavaScript - JavaScript BDD, JavaScript Generics, JavaScript I/O, JavaScript Serialization - JavaScript Deserialization, JavaScript APIs, JavaScript REST - JavaScript JSON - JavaScript GraphQL, JavaScript gRPC, JavaScript on the Server (Node.js-Deno-Express.js), JavaScript Virtualization, JavaScript Development Tools: JavaScript SDK, JavaScript Compiler - JavaScript Transpiler - Babel and JavaScript, JavaScript Interpreter - JavaScript REPL, JavaScript IDEs (Visual Studio Code, JavaScript Visual Studio Code, Visual Studio, JetBrains WebStorm, JetBrains JavaScript), JavaScript Debugging (Chrome DevTools), JavaScript Linter, JavaScript Community - JavaScriptaceans - JavaScript User, JavaScript Standard Library (core-js) - JavaScript Libraries (React.js-Vue.js-htmx, jQuery) - JavaScript Frameworks (Angular), JavaScript Testing - JavaScript TDD (JavaScript TDD, Selenium, Jest, Mocha.js, Jasmine, Tape Testing (test harness), Supertest, React Testing Library, Enzyme.js React Testing, Angular TestBed), JavaScript History, JavaScript Research, JavaScript Topics, JavaScript Uses - List of JavaScript Software - Written in JavaScript - JavaScript Popularity, JavaScript Bibliography - Manning JavaScript Series- JavaScript Courses, JavaScript Glossary - JavaScript Official Glossary - Glossaire de JavaScript - French, TypeScript, Web Browser, Web Development, HTML-CSS, JavaScript GitHub, Awesome JavaScript, JavaScript Versions. (navbar_javascript - see also navbar_web_development, navbar_javascript_networking, navbar_javascript_versions, navbar_javascript_standard_library, navbar_javascript_libraries, navbar_javascript_reserved_words, navbar_javascript_functional, navbar_javascript_concurrency, navbar_javascript async, navbar_typescript)