php - How to dynamically combine two arrays while making sure that they're evenly distributed? -

i'm trying combine 2 arrays have second array evenly distributed in first array. i'm open not merging them if there's nice loop solution i'm trying solve build new array.

array 1 looks this:

    $array_1 = array(         array('cat'),         array('cat'),         array('cat'),         array('cat'),         array('cat'),         array('cat'),         array('cat'),         array('cat'),         array('cat'),         array('cat'),         array('cat'),         array('cat'),         array('cat'),         array('cat'),         array('cat'),         array('cat'),         array('cat'),         array('cat'),         array('cat'),         array('cat'),         array('cat'),         array('cat'),         array('cat'),         array('cat'),         array('cat'),         array('cat'),         array('cat')     ); 

array 2 looks like:

$array_2 = array(     array('dog'),     array('dog'),     array('dog'),     array('dog') ); 

i want merge these one. kicker want evenly space out array 2 in array 1. illustrate question, like:

    $array_1 = array(         array('cat'),         array('cat'),         array('cat'),         array('cat'),         array('cat'),         array('cat'),          array('dog'),          array('cat'),         array('cat'),         array('cat'),         array('cat'),         array('cat'),         array('cat'),          array('dog'),          array('cat'),         array('cat'),         array('cat'),         array('cat'),         array('cat'),         array('cat'),          array('dog'),          array('cat'),         array('cat'),         array('cat'),         array('cat'),         array('cat'),         array('cat'),          array('dog'),          array('cat'),         array('cat'),         array('cat')     ); 

this needs dynamic since don't know size of array 1 or 2 (they change in time). needs account odd or , distributed possible. true constant array 2 shorter array 1.

the repeating arrays cat , dog illustrative purposes. actual values of these arrays can assume each it's own.

you can use following function. assumed elements in both arrays may have different values , array keys may not ordered.

function distribute($container, $distributed) {      // reindex arrays     $container = array_values($container);     $distributed = array_values($distributed);      $containersize = count($container);     $distributedsize = count($distributed);      $partsize = floor($containersize / $distributedsize);      $newarray = array();      $distributedkey = 0;     $newarraykey = 0;      foreach ($container $containerkey => $containervalue) {          if (($containerkey >= $partsize) && (($containerkey % $partsize) == 0)) {              $newarray[$newarraykey] = $distributed[$distributedkey][0];             $distributedkey++;             $newarraykey++;          }          $newarray[$newarraykey] = $container[$containerkey][0];         $newarraykey++;      }  return $newarray;  }