The java.lang.Math.signum() returns the Sign function of a value passed to it as argument. The signum() function returns the following values depending on the argument passed to it:
- If the argument passed is greater than zero, then the signum() function will return 1.0.
- If the argument passed is equal to zero, then the signum() function will return 0.
- If the argument passed is less than zero, then the signum() function will return -1.0.
Note: If the argument passed is NaN, then the result is NaN. If the argument passed is positive zero or negative zero then the result will be same as that of the argument.
Syntax:
public static double signum(double d) Parameter : a : the value whose signum function is to be returned. Return : This method returns the signum function value of the argument passed to it.
Example 1 : To show working of java.lang.Math.signum() method.
// Java program to demonstrate working// of java.lang.Math.signum() methodimport java.lang.Math;  class Gfg {      // driver code    public static void main(String args[])    {        // when the argument is greater than zero        double a = 30;        System.out.println(Math.signum(a));          // when the argument is equals to zero        a = 0;        System.out.println(Math.signum(a));          // when the argument is less than zero        a = -30;        System.out.println(Math.signum(a));    }} |
Output:
1.0 0 -1.0
Example 2 : To show working of java.lang.Math.signum() method when argument is NaN.
// Java program to demonstrate working// of java.lang.Math.signum() methodimport java.lang.Math; // importing java.lang package  public class GFG {    public static void main(String[] args)    {          double nan = Double.NaN;        double result;          // Here argument is NaN, output will be NaN        result = Math.signum(nan);        System.out.println(result);          // Here argument is positive zero        result = Math.signum(0);        System.out.println(result);          // Here argument is negative zero        result = Math.signum(-0);        System.out.println(result);    }} |
Output:
NaN 0.0 0.0
