# Java signum Function

The Java signum Function is one of the Math Library functions, which is to find the Sign of a given expression, i.e., Positive, Negative, or Zero. In this article, we will show how to use Math.signum function in Java Programming language with an example.

## Java signum Syntax

The basic syntax of the Math.signum Function in Java Programming language is as shown below:

`Math.signum(data_type number);`
• If the number argument is a positive or negative Zero, the Math.signum function will return Zero as an output.
• If the number argument is a Negative Number, it will return the Negative One(-1) as output.
• When a number argument is a positive number, it will return the Positive One(+1) as the output.
• If it is not a number, it will return NaN.

Java Programming provides two different Math.signum functions to return the Sign of a given expression. The below function will accept a positive or negative double value as an argument and returns the result.

```static double signum(double number); //Return type is double

// To use in program:
Math.signum(double number);```

The below function will accept positive or negative float value as an argument and returns the sign of the value.

```static float signum(float number); //Return Type is float

// To use in program:
Math.signum(float number);```

## Java signum Function Example

The Math.signum function returns the Sign of a specified expression. In this Java example, We are going to check the same for different data types and display the output.

```package MathFunctions;

public class SIgnumMethod {
public static void main(String[] args) {
double a = 44.5222, b = -698.6674;
float c = 56.23f, d = - 80.90f;

System.out.println("\nSignum Function result of Zero: " + Math.signum(0));

System.out.println("\nSignum Function of result Positive Double Value: " + Math.signum(a));
System.out.println("Signum Function of result Negative Double Value: " + Math.signum(b));

System.out.println("\nSignum Function of result Positive Float Value: " + Math.signum(c));
System.out.println("Signum Function of result Negative Float Value: " + Math.signum(d));

double e = Math.signum(10.90 + 15.10 - 20.50 + 1.50);
System.out.println("\nSignum Function results = " + e);
}
}```

First, We used this Java Function on Zero.

Next, We used the Java Math.signum Function on variables a and b (they belong to double type). It will call the double type ( static double signum(double number) ) method to return the sign value.

```System.out.println("\nNextUp result of Positive Doubles: " + Math.nextUp(a));
System.out.println("NextUp result of Negative Double Values: " + Math.nextUp(b));```

Next, We used the signum Math function on variables c and d (they belong to float type). The below statements will call the float type method ( static float signum(float number) ) to return the Sign value.

```System.out.println("\nSignum Function of result Positive Float Value: " + Math.signum(c));
System.out.println("Signum Function of result Negative Float Value: " + Math.signum(d));```

Lastly, variables of type Double were declared, and then we used the Math.signum function directly on expression.

`double a = Math.signum(10.90 + 15.10 - 20.50 + 1.50);`