The keys() method returns a new Array Iterator object that contains the keys for each index in the array.
Syntax
arr.keys()
Return value
A new Array Iterator
object.
Examples
Iteration using for...of loop
var arr = new Uint8Array([10, 20, 30, 40, 50]);
var eArray = arr.keys();
// your browser must support for..of loop
// and let-scoped variables in for loops
for (let n of eArray) {
console.log(n);
}
Alternative iteration
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
Specifications
| Specification | Status | Comment |
|---|---|---|
| ECMAScript 2015 (6th Edition, ECMA-262) The definition of '%TypedArray%.prototype.keys()' in that specification. |
Standard | Initial definition. |
| ECMAScript 2017 Draft (ECMA-262) The definition of '%TypedArray%.prototype.keys()' in that specification. |
Draft |
Browser compatibility
| Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari |
|---|---|---|---|---|---|
| Basic support | (Yes) | 37 (37) | No support | No support | No support |
| Feature | Android | Chrome for Android | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
|---|---|---|---|---|---|---|
| Basic support | No support | (Yes) | 37.0 (37) | No support | No support | No support |