keys()方法返回新的 Array Iterator 对象,包含数组中每个下标的键。
语法
arr.keys()
返回值
新的Array Iterator对象
示例
使用for...of循环的迭代
var arr = new Uint8Array([10, 20, 30, 40, 50]);
var eArray = arr.keys();
// 你的浏览器必须支持 for..of 循环
// 以及 for 循环中的 let 区域变量
for (let n of eArray) {
console.log(n);
}
备选的迭代
var arr = new Uint8Array([10, 20, 30, 40, 50]); var eArr = arr.keys(); console.log(eArr.next().value); // 0 console.log(eArr.next().value); // 1 console.log(eArr.next().value); // 2 console.log(eArr.next().value); // 3 console.log(eArr.next().value); // 4
规范
| Specification | Status | Comment |
|---|---|---|
| ECMAScript 2015 (6th Edition, ECMA-262) %TypedArray%.prototype.keys() |
Standard | 初始定义。 |
| ECMAScript Latest Draft (ECMA-262) %TypedArray%.prototype.keys() |
Draft |
浏览器兼容性
We're converting our compatibility data into a machine-readable JSON format. This compatibility table still uses the old format, because we haven't yet converted the data it contains.
Find out how you can help!
| Feature | Chrome | Edge | Firefox (Gecko) | Internet Explorer | Opera | Safari |
|---|---|---|---|---|---|---|
| Basic support | (Yes) | (Yes) | 37 (37) | 未实现 | 未实现 | 10 |
| Feature | Android | Chrome for Android | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
|---|---|---|---|---|---|---|
| Basic support | 未实现 | (Yes) | 37.0 (37) | 未实现 | 未实现 | 10 |