Addition (+)

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

L'opérateur d'addition (+) produit la somme de deux opérandes numériques ou la concaténation de deux chaînes de caractères.

Exemple interactif

console.log(2 + 2);
// Expected output: 4

console.log(2 + true);
// Expected output: 3

console.log("hello " + "everyone");
// Expected output: "hello everyone"

console.log(2001 + ": A Space Odyssey");
// Expected output: "2001: A Space Odyssey"

Syntaxe

js
Opérateur: x + y;

Exemples

Addition numérique

js
// Number + Number -> addition
1 + 2; // 3

// Boolean + Number -> addition
true + 1; // 2

// Boolean + Boolean -> addition
false + false; // 0

Concaténation de chaînes de caractères

js
// String + String -> concatenation
"toto" + "truc"; // "tototruc"

// Number + String -> concatenation
5 + "toto"; // "5toto"

// String + Boolean -> concatenation
"toto" + false; // "totofalse"

Spécifications

Specification
ECMAScript® 2025 Language Specification
# sec-addition-operator-plus

Compatibilité des navigateurs

Report problems with this compatibility data on GitHub
desktopmobileserver
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
Deno
Node.js
Addition (+)

Legend

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Full support
Full support

Voir aussi