Question

This is sort of two questions, but there may be one overall answer for the whole problem. I have an array that I need to append onto another array. Both arrays must have specific numeric keys. My problems are:

1. I need the numeric keys for the array that I am appending onto to be preserved.
   • array_splice() and array_merge() won’t work to join the arrays because numeric keys in both arrays will be reset.
2. I need to make the keys of the newly added elements to be n through n + x, meaning if n is 100 and x is 25, the keys for the newly added elements should be 100 through 125.

Can anyone think of a somewhat efficient way of doing this?

EDIT

For anyone curious, found a better way of adding the correct keys to the array.

// add correct keys
$array_segment = array_combine(range($offset, $offset + count($array_segment) - 1), $array_segment);
// merge arrays while maintaining keys
$first_array = $first_array + $array_segment;

Answer 1

I think this is a very simple solution but, if I understand well what you want, it works and it’s fast. In my opinion you can use this approach:

$array1 = array(1 => 'a', 2 => 'b', 3 => 'c');
$array2 = array(4 => 'd', 5 => 'e', 6 => 'f');

foreach($array2 as $key => $value)
   $array1[$key] = $value;

var_dump($array1);

$array1[] = 'g';
$array1[] = 'h';

var_dump($array1);

You can see the result here:

http://codepad.org/ogD9drpK

Another way which will avoid the foreach is to execute this instruction:

// avoid the loop
//foreach($array2 as $key => $value)
//   $array1[$key] = $value;
$array1 += $array2;

You can see the result here:

http://codepad.org/cZxCfRn6