key

Fetch a key from an array

&reftitle.description; ``int``string``null```key` ``array``object```array`

`key` returns the index element of the current array position.

&reftitle.parameters;

`array`

- The array.

&reftitle.returnvalues;

The `key` function simply returns the key of the array element that's currently being pointed to by the internal pointer. It does not move the pointer in any way. If the internal pointer points beyond the end of the elements list or the array is empty, `key` returns &null;.

&reftitle.changelog;

&Version; | &Description;
&standard.changelog.calling-on-objects;

&reftitle.examples;

### `key` example

    <?php
    $array = array(
        'fruit1' => 'apple',
        'fruit2' => 'orange',
        'fruit3' => 'grape',
        'fruit4' => 'apple',
        'fruit5' => 'apple');

    // this cycle echoes all associative array
    // key where value equals "apple"
    while ($fruit_name = current($array)) {
        if ($fruit_name == 'apple') {
            echo key($array), "\n";
        }
        next($array);
    }
    ?>

&example.outputs;

    fruit1
    fruit4
    fruit5

&reftitle.seealso;

- `current`
- `next`
- `array_key_first`
- foreach