Web/JavaScript/Reference/Operators/Inequality

The inequality operator (!=) checks whether its two operands are not equal, returning a Boolean result. Unlike the strict inequality operator, it attempts to convert and compare operands that are of different types.

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Syntax

x != y

Description

The inequality operator checks whether its operands are not equal. It is the negation of the equality operator so the following two lines will always give the same result:

x != y

!(x == y)

For details of the comparison algorithm, see the page for the equality operator.

Like the equality operator, the inequality operator will attempt to convert and compare operands of different types:

3 != "3"; // false

To prevent this, and require that different types are considered to be different, use the strict inequality operator instead:

3 !== "3"; // true

Examples

Comparison with no type conversion

1 != 2;              // true
"hello" != "hola";   // true

1 != 1;              // false
"hello" != "hello";  // false

Comparison with type conversion

"1" !=  1;            // false
1 != "1";             // false
0 != false;           // false
0 != null;            // true
0 != undefined;       // true
0 != !!null;          // false, look at Logical NOT operator 
0 != !!undefined;     // false, look at Logical NOT operator 
null != undefined;    // false

const number1 = new Number(3);
const number2 = new Number(3);
number1 != 3;         // false
number1 != number2;   // true

Comparison of objects

const object1 = {"key": "value"}
const object2 = {"key": "value"};

object1 != object2 // true
object2 != object2 // false

Specifications

Specification

ECMAScript (ECMA-262)The definition of 'Equality operators' in that specification.

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile						Server
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet	Node.js
Inequality (`a != b`)	Chrome Full support 1	Edge Full support 12	Firefox Full support 1	IE Full support 3	Opera Full support 3	Safari Full support 1	WebView Android Full support 1	Chrome Android Full support 18	Firefox Android Full support 4	Opera Android Full support 10.1	Safari iOS Full support 1	Samsung Internet Android Full support 1.0	nodejs Full support 0.1.100

Legend

Full support: Full support