Long signum() Method in Java

The signum function also known as sign function is an odd mathematical function that extracts the sign of a real number.
The java.lang.Long.signum() method is used to get the signum function of the specified long value. For a positive value, a negative value and zero, the method returns 1, -1 and 0 respectively.

Syntax :

public static int signum(long num)

Parameters: The method accepts one parameter num of long type on which the signum operation is to be performed.

Return Value: The method returns the signum function of the specified long value. If the specified value is:

• Negative, the method returns -1.
• Zero, the method returns 0.
• Positive, the method returns 1.

Examples:

Input: (Long) 2731766
Output: 1

Input: (Long) -233611 
Output: -1

Input: (Long) 0
Output: 0

Below programs illustrate the Java.lang.Long.signum() Method:
Program 1:

// Java program to illustrate the
// Java.lang.Long.signum() Method
import java.lang.*;

public class Geeks {

    public static void main(String[] args)
    {

        // It will return 1 as long value is greater than 1
        System.out.println(Long.signum(36565531));

        // It will return -1 as long value is less than 1
        System.out.println(Long.signum(-628127));

        // Returns 0 as long value is equal to 0
        System.out.println(Long.signum(0));
    }
}

Output:

1
-1
0

Program 2: For decimal value and string.

// Java program to illustrate the
// Java.lang.Long.signum() Method
import java.lang.*;

public class Geeks {

    public static void main(String[] args)
    {

        // It will return compile time error
        System.out.println(Long.signum(36565.531));

        // It will return compile time error
        System.out.println(Long.signum("628127"));
    }
}

Output:

prog.java:10: error: incompatible types: possible lossy conversion from double to long
    System.out.println(Long.signum(36565.531));
                                   ^
prog.java:13: error: incompatible types: String cannot be converted to long
    System.out.println(Long.signum("628127"));
                                   ^
Note: Some messages have been simplified; recompile with -Xdiags:verbose to get full output
2 errors