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 GitHubdesktop | mobile | server | ||||||||||||
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clear |
Legend
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- Full support
- Full support
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