Java Math.copySign() method

The java.lang.Math.copySign () is used to return the first argument with the sign of the second argument.

Syntax

public static double copySign(double a, double b)
public static float copySign(float a, float b)

Parameter

a = the argument providing the magnitude of the result
b = the argument providing the sign of the result

Return

This method returns the magnitude of the first argument with the sign of the second argument.

Example 1

public class CopySignExample1
{
    public static void main(String[] args) 
    {
        double x = 740.4;
        double y = -29.1;
        // return -740.4 because second argument is negative  
        System.out.println(Math.copySign(x, y));
    }
}

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Output:

-740.4

Example 2

public class CopySignExample2
{
    public static void main(String[] args) 
    {
        double x = -580.73;
        double y = 26.3;
        // return 580.73 because second argument y is positive
        System.out.println(Math.copySign(x, y));
    }
}

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Output:

580.73

Example 3

public class CopySignExample3
{
    public static void main(String[] args) 
    {
        float x = -788.63f;
        float y = 26.9f;
        // return -26.9 because second argument x is negative
        System.out.println(Math.copySign(y, x));
    }
}

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Output: