The signum function is an odd mathematical function that extracts the sign of a real number. The signum function is also known as sign function.
The Integer.signum() method of java.lang returns the signum function of the specified integer value. For a positive value, a negative value and zero the method returns 1, -1 and 0 respectively.
Syntax :
public static int signum(int a)
Parameter: The method takes one parameter a of integer type on which the operation is to be performed.
Return Value: The method returns the signum function of the specified integer value. If the specified value is negative it returns -1, 0 if the specified value is zero, and 1 if the specified value is positive.
Examples:
Consider an integer a = 27 Since 27 is a positive int signum will return= 1 Consider another integer a = -61 Since -61 is a negative int signum will return= -1 Consider the integer value a = 0 For a zero signum, it will return = 0
Below programs illustrate the Java.lang.Integer.signum() Method:
Program 1:
// Java program to illustrate the // Java.lang.Integer.signum() Method import java.lang.*;
public class Geeks {
public static void main(String[] args) {
// It will return 1 as the int value is greater than 1
System.out.println(Integer.signum( 1726 ));
// It will return -1 as the int value is less than 1
System.out.println(Integer.signum(- 13 ));
// It will returns 0 as int value is equal to 0
System.out.println(Integer.signum( 0 ));
} } |
1 -1 0
Program 2:
// Java program to illustrate the // Java.lang.Integer.signum() Method import java.lang.*;
public class Geeks {
public static void main(String[] args) {
// It will return 1 as the int value is greater than 1
System.out.println(Integer.signum(- 1726 ));
// It will return -1 as the int value is less than 1
System.out.println(Integer.signum( 13 ));
// It will returns 0 as int value is equal to 0
System.out.println(Integer.signum( 0 ));
} } |
-1 1 0
Program 3: For a decimal value and string.
Note: It returns an error message when a decimal value and string is passed as an argument.
// Java program to illustrate the // Java.lang.Integer.signum() Method import java.lang.*;
public class Geeks {
public static void main(String[] args) {
//returns compile time error as passed argument is a decimal value
System.out.println(Integer.signum( 3.81 ));
//returns compile time error as passed argument is a string
System.out.println(Integer.signum( "77" ));
} } |
prog.java:10: error: incompatible types: possible lossy conversion from double to int System.out.println(Integer.signum(3.81)); ^ prog.java:14: error: incompatible types: String cannot be converted to int System.out.println(Integer.signum("77")); ^ Note: Some messages have been simplified; recompile with -Xdiags:verbose to get full output 2 errors