title: Merge all sub arrays into one
body: <p>I'm looking to find a way to merge all child arrays into one large array. </p>
  
  <pre><code>array (
      [0] = 
           [0] = '0ARRAY',
           [1] = '1ARRAY'
      [1] = 
           [0] = '2ARRAY',
           [1] = '3ARRAY'
  )
  </code></pre>
  
  <p>into </p>
  
  <pre><code>array (
      [0] = '0ARRAY', [1] = '1ARRAY', [2] = '2ARRAY', [3] = '3ARRAY'
  )
  </code></pre>
  
  <p>Without using <code>array_merge($array[0],$array[1])</code> because I don't know how many arrays there actually are. So I wouldn't be able to specify them. </p>
  
  <p>Thanks</p>