JavaScript Array keys()
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Definition and Usage
keys() The method returns an Array Iterator object with the array keys.
Note:keys() The method does not change the original array.
Example
Create an Array Iterator object that only contains the keys of the array, and then iterate over each key:
var fruits = ["Banana", "Orange", "Apple", "Mango"];
var fk = fruits.keys();
for (x of fk) {
document.getElementById("demo").innerHTML += x + "<br>";
}
Syntax
array.keys()
Parameters
No parameters.
Technical Details
| Return value: | Array Iterator object |
|---|---|
| JavaScript Version: | ECMAScript 6 |
Browser Support
The numbers in the table indicate the first browser version that fully supports this method.
| Chrome | Edge | Firefox | Safari | Opera |
|---|---|---|---|---|
| Chrome 38 | Edge 12 | Firefox 28 | Safari 8 | Opera 25 |
| October 2014 | July 2015 | March 2014 | October 2014 | October 2014 |
Note:Internet Explorer does not support keys() Methods.
Related Pages
Tutorial:JavaScript Array
Tutorial:JavaScript Array Const
Tutorial:JavaScript Array Methods
Tutorial:JavaScript Sorting Array
Tutorial:JavaScript Array Iteration
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