Question

I often run into this situation:

foreach ($someObjects as &$someObject)
{
  $someObjectsIndex[$someObject->id] = $someObject;
}

And this:

$thingsIActuallyWant = [];
foreach ($associativeList as &$associativeItem)
{
  $thingsIActuallyWant[] = $associativeItem['id'];
}

I was wondering if there is an existing method or something to write these things shorter, without writing the foreach loop.

Answer 1

You can use array_map to return you an array of just the elements you want.

For the 2nd example:

$thingsIActuallyWant = array_map(function($a){
    return $a['id'];
}, $associativeList);

As for the 1st, I suggest using the foreach as you have, because any alternative is going to be an ugly mess of array_map and array_combine.