Map.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 July 2015.

Map 实例的 clear() 方法会移除该 map 中的所有元素。

尝试一下

const map1 = new Map();

map1.set("bar", "baz");
map1.set(1, "foo");

console.log(map1.size);
// Expected output: 2

map1.clear();

console.log(map1.size);
// Expected output: 0

语法

js
clear()

参数

无。

返回值

无(undefined)。

示例

使用 clear()

js
const myMap = new Map();
myMap.set("bar", "baz");
myMap.set(1, "foo");

console.log(myMap.size); // 2
console.log(myMap.has("bar")); // true

myMap.clear();

console.log(myMap.size); // 0
console.log(myMap.has("bar")); // false

规范

Specification
ECMAScript® 2025 Language Specification
# sec-map.prototype.clear

浏览器兼容性

Report problems with this compatibility data on GitHub
desktopmobileserver
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
Deno
Node.js
clear

Legend

Tip: you can click/tap on a cell for more information.

Full support
Full support

参见