PHP - 从其他密钥获取密钥值

Question

I have the following array:

$array = Array(
    "0" => Array (
        "id" => 1081,
        "name" => "John"
    ), 
    "1" => Array (
        "id" => 1082,
        "name" => "Matt"
    ),
    "2" => Array (
        "id" => 1083,
        "name" => "Roger"
    )
);

Is there anyway I can get name if I only know the id but without having to iterate through the array?

Answer 1

You can make an associative array that refers to the same elements, then use that:

function make_assoc(&$array, $keyname) {
    $new_array = array();
    foreach ($array as &$elt) {
        $new_array[$elt[$keyname]] = $elt;
    }
    return $new_array;
}

$assoc_array = make_assoc($array, 'id');

Now you can use $assoc_array[1083] to access the third item in the original array. And since this returns an array of references, modifying that will also modify the element of the original array.