JavaScript Array keys()
Example
Create an Array Iterator object, containing the keys of the array:
const fruits = ["Banana", "Orange", "Apple", "Mango"];
const keys = fruits.keys();
let text = "";
for (let x of keys) {
text += x + "<br>";
}
Try it Yourself »
Use the built in Object.keys() Method:
const fruits = ["Banana", "Orange", "Apple", "Mango"];
const keys = Object.keys(fruits);
let text = "";
for (let x of keys) {
text += x + "<br>";
}
Try it Yourself »
Definition and Usage
The keys() method returns an Array Iterator object with the keys of an array.
The keys() method does not change the original array.
Syntax
array.keys()
Parameters
| NONE |
Return Value
| Type | Description |
| An array | An Array Iterator object containing the keys of an array. |
Browser Support
keys() is an ECMAScript6 (ES6) feature.
ES6 (JavaScript 2015) is supported in all modern browsers:
| Chrome | Edge | Firefox | Safari | Opera |
| Yes | Yes | Yes | Yes | Yes |
keys() is not supported in Internet Explorer 11 (or earlier).
