Java NOT (!) Operator

Java NOT

Java NOT Operator is used to invert the value of a boolean value.

NOT Operator Symbol

The symbol used for NOT Operator is !.

Syntax

The syntax to use NOT Operator with an operand a is

!a

a can be a Boolean variable, or boolean expression, or a complex condition.

NOT Truth Table

The following truth table provides the output of NOT operator for different values of operands.

a	!a
true	false
false	true

NOT Operator negates the given value.

Examples

In the following example, we take a boolean variable with different values: true and false, and find their logical NOT output.

Main.java

public class Main {
    public static void main(String[] args) {
        boolean a, result;
        
        a = true;
        result = !a;
        System.out.println("!" + a + "  = " + result);
        
        a = false;
        result = !a;
        System.out.println("!" + a + " = " + result);
    }
}

Output

!true  = false
!false = true

In the following example, we will use NOT operator for a boolean condition in If Statement.

index.html

public class Main {
    public static void main(String[] args) {
        int a = 4;
        if (!(a % 2 == 1)) {
            System.out.println("a is not odd.");
        } else {
            System.out.println("a is odd.");
        }
    }
}

Output

a is not odd.

Conclusion

In this JavaScript Tutorial, we learned about Logical NOT Operator, its syntax, and usage with examples.