Change array key without changing order

Question

You can \"change\" the key of an array element simply by setting the new key and removing the old:

$array[$newKey] = $array[$oldKey];
unset($array[$oldKey]);         


        

Answer 1

One way would be to simply use a foreach iterating over the array and copying it to a new array, changing the key conditionally while iterating, e.g. if $key === 'foo' then dont use foo but bar:

function array_key_rename($array, $oldKey, $newKey) 
{
    $newArray = [];
    foreach ($array as $key => $value) {
        $newArray[$key === $oldKey ? $newKey : $key] = $value;
    }
    return $newArray;
}

Another way would be to serialize the array, str_replace the serialized key and then unserialize back into an array again. That isnt particular elegant though and likely error prone, especially when you dont only have scalars or multidimensional arrays.

A third way - my favorite - would be you writing array_key_rename in C and proposing it for the PHP core ;)