Set.prototype.clear()

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since 2015年7月.

clear() 方法會從一個 Set 物件中移除其所有元素。

嘗試一下

const set1 = new Set();
set1.add(1);
set1.add("foo");

console.log(set1.size);
// Expected output: 2

set1.clear();

console.log(set1.size);
// Expected output: 0

語法

mySet.clear();

回傳值

undefined。

範例

使用 clear 方法

js
var mySet = new Set();
mySet.add(1);
mySet.add("foo");

mySet.size; // 2
mySet.has("foo"); // true

mySet.clear();

mySet.size; // 0
mySet.has("bar"); // false

規範

Specification

ECMAScript® 2027 Language Specification
# sec-set.prototype.clear

瀏覽器相容性

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參見

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This page was last modified on 2025年7月14日 by MDN contributors.

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Set.prototype.clear()

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