title: How to "flatten" a multi-dimensional array to simple one in PHP?
body: <p>It's probably beginner question but I'm going through documentation for longer time already and I can't find any solution. I thought I could use implode for each dimension and then put those strings back together with <code>str_split</code> to make new simple array. However I never know if the join pattern isn't also in values and so after doing <code>str_split</code> my original values could break.</p>
  
  <p>Is there something like <code>combine($array1, $array2)</code> for arrays inside of multi-dimensional array?</p>