The size accessor property returns the number of elements in a Set object.
The value of size is an integer representing how many entries the Set object has. A set accessor function for size is undefined; you cannot change this property.
size
var mySet = new Set();
mySet.add(1);
mySet.add(5);
mySet.add('some text')
mySet.size; // 3
| Specification | Status | Comment |
|---|---|---|
| ECMAScript 2015 (6th Edition, ECMA-262) The definition of 'Set.prototype.size' in that specification. | Standard | Initial definition. |
| ECMAScript Latest Draft (ECMA-262) The definition of 'Set.prototype.size' in that specification. | Draft |
| Feature | Chrome | Edge | Firefox | Internet Explorer | Opera | Safari |
|---|---|---|---|---|---|---|
| Basic support | 38 | 12 | 191 | 11 | 25 | 8 |
| Feature | Android webview | Chrome for Android | Edge mobile | Firefox for Android | Opera Android | iOS Safari | Samsung Internet |
|---|---|---|---|---|---|---|---|
| Basic support | 38 | 38 | 12 | 191 | 25 | 8 | ? |
1. From Firefox 13 to Firefox 18, the size property was implemented as a Set.prototype.size() method, this has been changed to a property in later versions conform to the ECMAScript 2015 specification.
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https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Set/size