Suppose you have two (numeric) arrays $a and $b and want to achieve what you get by doing
$a = & array_merge($a, $b);
efficiently.
Is this already the way to do it? I find array_merge suspicious because it merges associative keys. Also I suppose the array is not updated but copied unnecessarily. Is there a way to call array_push with an array? Or would you do it in a loop with $a[] = ... assignments?
array_merge will reindex keys. To maintain keys, use $c = $array1 + $array2. If $array2 has an existing key, it will be ignored. You can also array_push, array_pop, array_shift, and array_unshift for item addition and subtraction.