Map.prototype.keys()
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.
尝试一下
const map1 = new Map();
map1.set("0", "foo");
map1.set(1, "bar");
const iterator1 = map1.keys();
console.log(iterator1.next().value);
// Expected output: "0"
console.log(iterator1.next().value);
// Expected output: 1
语法
js
keys()
参数
无。
返回值
一个新的可迭代迭代器对象。
示例
使用 keys()
js
const myMap = new Map();
myMap.set("0", "foo");
myMap.set(1, "bar");
myMap.set({}, "baz");
const mapIter = myMap.keys();
console.log(mapIter.next().value); // "0"
console.log(mapIter.next().value); // 1
console.log(mapIter.next().value); // {}
规范
Specification |
---|
ECMAScript® 2025 Language Specification # sec-map.prototype.keys |
浏览器兼容性
Report problems with this compatibility data on GitHubdesktop | mobile | server | ||||||||||||
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keys |
Legend
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- Full support
- Full support
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