基于唯一值php重新排列关联数组

Question

Given this:

array("Peter"=>"Marketing", "Clark"=>"Accounts", "John"=>"Accounts");

I would like to get an array with following result:

array(2) { ["Marketing"]=> array(1) { [0]=> "Peter" } ["Accounts"]=> array(2) { [0]=> "Clark" [1]=> "John" } }

What i have tried so far ->

$rearrange = array();
foreach($array as $key => $val) {
  if(array_key_exists($key,$array)) {
     $rearrange[$value] = $key;
  }
 }

Answer 1

Not sure why the array_key_exists but you almost had it:

foreach($array as $key => $val) {
    $rearrange[$val][] = $key;
}

• You foreach as $val but then use $value which doesn't exist
• You need to dynamically append a new element []