Q:

PHP Group array by values

I have an array like this:
Array ( 
     [0] => ing_1_ing 
     [1] => ing_1_amount 
     [2] => ing_1_det 
     [3] => ing_1_meas
     [4] => ing_2_ing 
     [5] => ing_2_amount 
     [6] => ing_2_det 
     [7] => ing_2_meas 
)

And I want to group the values into an array like this:
Array (
   [0] => Array(
             [0] => ing_1_ing
             [1] => ing_1_amount
             [2] => ing_1_det
             [3] => ing_1_meas
          )
   [1] => Array(
             [0] => ing_2_ing
             [1] => ing_2_amount
             [2] => ing_2_det
             [3] => ing_2_meas
          )
)

There may be many other items named like that: ing_NUMBER_type
How do I group the first array to the way I want it?  I tried this, but for some reason, strpos() sometimes fails:
$i = 1;     
foreach ($firstArray as $t) {
            if (strpos($t, (string)$i)) {
                $secondArray[--$i][] = $t;
            } else {
                $i++;
            }
        }

What is wrong?  Can you advice? 

A:

It depends what you are trying to achieve, if you want to split array by chunks use array_chunk method and if you are trying to create multidimensional array based on number you can use sscanf method in your loop to parse values:
$result = array();

foreach ($firstArray as $value)
{
    $n = sscanf($value, 'ing_%d_%s', $id, $string);

    if ($n > 1)
    {
        $result[$id][] = $value;
    }
}

