The size
accessor property returns the number of elements in a Map
object.
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Description
The value of size
is an integer representing how many entries the Map
object has. A set accessor function for size
is undefined
; you can not change this property.
Examples
Using size
var myMap = new Map(); myMap.set('a', 'alpha'); myMap.set('b', 'beta'); myMap.set('g', 'gamma'); myMap.size // 3
Specifications
Specification |
---|
ECMAScript (ECMA-262) The definition of 'Map.prototype.size' 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 | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
size | Chrome Full support 38 | Edge Full support 12 | Firefox
Full support
19
| IE Full support 11 | Opera Full support 25 | Safari Full support 8 | WebView Android Full support 38 | Chrome Android Full support 38 | Firefox Android
Full support
19
| Opera Android Full support 25 | Safari iOS Full support 8 | Samsung Internet Android Full support 3.0 | nodejs Full support 0.12 |
Legend
- Full support
- Full support
- See implementation notes.
- See implementation notes.