PHP merge array by same value

Question

I have two big arrays with around 1000 keys and every day growing. How can I merge this arrays into one by value in array1[]['uid'] and array2[][7]

Please note that correct value could be for example array1[45]['uid'] and array2[155][7] or array1[444]['uid'] and array2[666][7] etc.

array1
    0 => 
    array
      'login' => string '104' (length=5)
      'uid' => string '1363861889.100' (length=14)
    1 => 
    array
      'login' => string '131' (length=5)
      'uid' => string '1363863722.126' (length=14)
    etc...

and the other one

array2
     0 => 
    array
      0 => string '2013' (length=4)
      1 => string '03' (length=2)
      2 => string '25' (length=2)
      3 => string '15' (length=2)
      4 => string '39' (length=2)
      5 => string '49' (length=2)
      6 => string 'anonymous' (length=9)
      7 => string '1363863722.126' (length=19)
    1 => 
    array
      0 => string '2013' (length=4)
      1 => string '03' (length=2)
      2 => string '25' (length=2)
      3 => string '12' (length=2)
      4 => string '39' (length=2)
      5 => string '42' (length=2)
      6 => string 'anonymous' (length=9)
      7 => string '1363861889.100' (length=19)
    etc...

array1[0]['uid'] has the same value herearray2[1][7] I would like get:

 array
      0 => string '2013' (length=4)
      1 => string '03' (length=2)
      2 => string '25' (length=2)
      3 => string '12' (length=2)
      4 => string '39' (length=2)
      5 => string '42' (length=2)
      6 => string 'anonymous' (length=9)
      7 => string '1363861889.100' (length=19)
      'login' => string '104' (length=5)
      'uid' => string '1363861889.100' (length=14)

Answer 1

$array1_inverted = array();
foreach ($array1 as $subarray) {
  $array1_inverted[$subarray['uid']] = $subarray;
}
foreach ($array2 as &$element) {
  $array1_element = $array1_inverted[$element[7]];
  $element['uid'] = $array1_element['uid'];
  $element['login'] = $array1_element['login'];
}

DEMO