如何在PHP中交换键/值?

I've an array in the following format.

[records] => Array
    (
        [7] => Array
            (
                [available] => No
            )
        [8] => Array
            (
                [available] => No
            )            
        [9] => Array
            (
                [available] => No
            )
        [11] => Array
            (
                [available] => Yes
            )

    )

I need to interchange the Yes/No Values with the Array keys(7,8,9,11). Normally a loop would do the trick. However, I would like to know whether any other methods are available other than looping so that I could drop off the plan for an additional looping.

Try below code it's works for you.

$array=Array
    (
        [7] => Array
            (
                [available] => No
            )
        [8] => Array
            (
                [available] => No
            )            
        [9] => Array
            (
                [available] => No
            )
        [11] => Array
            (
                [available] => Yes
            )

    )
array_walk($array, function(&$value) {
    $value['available'] = "Yes";
});

also see http://php.net/manual/en/function.array-walk.php