Edd Mann Developer

An 'array_column' re-indexing trick in PHP

The array_column function has been a welcome addition to the PHP language, allowing us to remove the need for common-place array_map invocations that just pluck specific values from arrays. However, I just found out that you can provide a third argument that allows you to define what the returning arrays keys will be. This combined with null for the value argument allows you to easily re-index an array based on a key value whilst maintaining the original arrays values and ordering.

$arr = [
    ['id' => 123, 'name' => 'Joe'],
    ['id' => 345, 'name' => 'Sally']

array_column($arr, null, 'id'); // [ 123 => ['id' => 123, 'name' => 'Joe'] ...
array_column($arr, 'name', 'id'); // [ 123 => 'Joe', 345 => 'Sally' ...