php how to group a multidimensional array by a particular value?

[SnarkytoSnarkers]

Hopefully, I can explain this correctly...

 

I have a multidimensional array and am trying to group them according to the value of one the keys.

 

So, I'm trying to group them by level, but I won't actually know the level beforehand. So, it's not like I can put it in a for loop and say while $i < 7, because I won't know that 7 is the maximum value for the level key, and, frankly, I'm not sure that's how I would need to do it even if I did...

 

Array (
   [0] => Array (
          [cust] => XT8900
          [type] => standard
          [level] => 1
          )
   [1] => Array (
          [cust] => XT8944
          [type] => standard
          [level] => 1
          )
   [2] => Array (
          [cust] => XT8922
          [type] => premier
          [level] => 3
          )
   [3] => Array (
          [cust] => XT8816
          [type] => permier
          [level] => 3
          )
   [4] => Array (
          [cust] => XT7434
          [type] => standard
          [level] => 7
          )
)

 

What I'm hoping to produce:

 

Array (

   [1] => Array (
          [0] => Array (
                    [cust] => XT8900
                    [type] => standard
                    )
          [1] => Array (
                    [cust] => XT8944
                    [type] => standard
                    )
          )

   [3] => Array (
          [2] => Array (
                 [cust] => XT8922
                 [type] => premier
                 )

          [3] => Array (
                 [cust] => XT8816
                 [type] => permier
                 )
          )

   [7] => Array (
          [4] => Array (
                 [cust] => XT7434
                 [type] => standard
                 )
          )
)

 

 

[akitchin]

for lack of a fancier way, you should be able to do this with a foreach() loop:

 

$level_keys = array();
foreach ($master_array AS $k => $sub_array)
{
  $this_level = $sub_array['level'];
  $level_keys[$this_level][$k] = array('cust' => $sub_array['cust'], 'type' => $sub_array['type']);
}
'<pre>'.print_r($level_keys, TRUE).'</pre>';