Java Math.copySign() is a static method in the Java Math class that returns the first argument with the sign of the second argument. It is commonly used in numerical applications that require explicit sign adjustments. Introduced in Java 2007 with Java 7, copySign() is efficient for transferring signs between floating-point values without changing magnitudes.

https://docs.oracle.com/javase/8/docs/api/java/lang/Math.html