Storage: key() method

{{APIRef("Web Storage API")}}

The key() method of the {{domxref("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

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:

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:

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

{{Specifications}}

Browser compatibility

{{Compat}}

See also

• Using the Web Storage API