Logical NOT (!) Expression

Summary

Negates an expression.

Syntax

!expression

Parameters

expression: Any legal expression.

Description

The logical NOT (!) operator negates an expression. Therefore, if an expression evaluates to true, this operator applied to the expression will return false; if an expression evaluates to false, this operator applied to the expression will return true.

!true;  // false
!false; // true
!( 5 > 3 ); // false
!( 5 == 1); // true

Inequality (such as comparing if x does not equal y) can also be checked by using the inequality (!=) comparison and strict inequality (!==) comparison operators.

Usage in Conditional Statements

The logical NOT operator is commonly used in conditional statements, such as if statements, to test if conditions are true or false. For example:

import System;
 
bool x = false;
if (!x) {
    Console.log("'x' is false");
}