title: Implode data from a Two-dimensional array
body: <p>I think it should not be so difficult to solve but i can’t get the solution.</p>
  
  <p>I’m trying to implode an array in order to have this result :</p>
  
  <pre><code>$new_array = "755, 646, 648, 260, 257, 261, 271, 764, ..."
  </code></pre>
  
  <p>Here is my array :</p>
  
  <pre><code>Array
  (
      [0] =&gt; Array
          (
              [0] =&gt; 755
              [1] =&gt; 646
          )
  
      [1] =&gt; Array
          (
              [0] =&gt; 648
              [1] =&gt; 260
              [2] =&gt; 257
              [3] =&gt; 261
          )
  
      [2] =&gt; Array
          (
              [0] =&gt; 271
          )
  
      [3] =&gt; Array
          (
              [0] =&gt; 764
              [1] =&gt; 643
              [2] =&gt; 260
              [3] =&gt; 263
              [4] =&gt; 756
              [5] =&gt; 763
              [6] =&gt; 762
              [7] =&gt; 259
              [8] =&gt; 257
              [9] =&gt; 758
              [10] =&gt; 261
              [11] =&gt; 768
              [12] =&gt; 757
              [13] =&gt; 647
          )
  )
  </code></pre>
  
  <p>I know how to do this with a simple array :</p>
  
  <pre><code>$newarray = implode(", ", $array);
  </code></pre>
  
  <p>I know how to get the key (with <code>array_keys</code>)</p>
  
  <pre><code>$new_array = implode(", ", array_keys($array));
  </code></pre>
  
  <p>I’ve tried with <code>array_map</code> but without result for the moment.</p>
  
  <p>Coud you help me and point me in the right direction ?</p>