Java Math.signum()用法及代碼示例

public static double signum(double x)
public static float signum(float x)

x = It is a floating-point value whose signum is to be returned

This method returns the signum function of an argument

public class SignumExample1
{
    public static void main(String[] args) 
    {
        double a= 82.7;
        System.out.println(Math.signum(a));
    }
}

1.0

public class SignumExample2
{
    public static void main(String[] args) 
    {
        double a= -48.6;
        System.out.println(Math.signum(a));
    }
}

-1.0

public class SignumExample3
{
    public static void main(String[] args) 
    {
       float a= 0.0f;
        System.out.println(Math.signum(a));
    }
}

0.0

public class SignumExample4
{
    public static void main(String[] args) 
    {
        double a= 0.0/0;
        System.out.println(Math.signum(a));
    }
}

NaN