The addition operator (+
) produces the sum of numeric operands or string concatenation.
The source for this interactive example is stored in a GitHub repository. If you'd like to contribute to the interactive examples project, please clone https://github.com/mdn/interactive-examples and send us a pull request.
Syntax
Operator: x + y
Examples
Numeric addition
// Number + Number -> addition 1 + 2 // 3 // Boolean + Number -> addition true + 1 // 2 // Boolean + Boolean -> addition false + false // 0
String concatenation
// String + String -> concatenation 'foo' + 'bar' // "foobar" // Number + String -> concatenation 5 + 'foo' // "5foo" // String + Boolean -> concatenation 'foo' + false // "foofalse"
Specifications
Specification |
---|
ECMAScript (ECMA-262) The definition of 'Addition operator' in that specification. |
Browser compatibility
The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
Desktop | Mobile | Server | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Addition (+ ) | 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