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set.size

set.size

Size属性将会返回Set对象中元素的个数。

描述

Size的值表示Set对象拥有多少个元素。通过调用函数的形式访问Size会提示为undefined;并且该值不能够被更改。

示例

使用size

var mySet = new Set( mySet.add(1 mySet.add(5 mySet.add('some text') mySet.size; // 3

规范

SpecificationStatusComment
ECMAScript 2015 (6th Edition, ECMA-262)The definition of 'Set.prototype.size' in that specification.StandardInitial definition.
ECMAScript Latest Draft (ECMA-262)The definition of 'Set.prototype.size' in that specification.Draft

浏览器兼容性

FeatureChromeEdgeFirefox (Gecko)Internet ExplorerOperaSafari
Basic support38(Yes)19 (19) 111257.1

FeatureAndroidChrome for AndroidEdgeFirefox Mobile (Gecko)IE MobileOpera MobileSafari Mobile
Basic supportNo support38(Yes)19.0 (19)No supportNo support8