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Storage: key() method

The key() method of the Storage interface, when passed a number n, returns the name of the nth key in a given Storage object. The order of keys is user-agent defined, so you should not rely on it.

Syntax

js

key(index)

Parameters

index

An integer representing the number of the key you want to get the name of. This is a zero-based index.

Return value

A string containing the name of the key. If the index does not exist, null is returned.

Examples

The following function iterates over the local storage keys:

js

function forEachKey(callback) {
  for (let i = 0; i < localStorage.length; i++) {
    callback(localStorage.key(i));
  }
}

The following function iterates over the local storage keys and gets the value set for each key:

js

for (let i = 0; i < localStorage.length; i++) {
  console.log(localStorage.getItem(localStorage.key(i)));
}

Note: For a real-world example, see our Web Storage Demo.

Specifications

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
key 4 12 3.5 8 10.5 4 ≤37 18 6 11 3.2 1.0

See also

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https://developer.mozilla.org/en-US/docs/Web/API/Storage/key