title: array_combine removed duplicate array
body: <p>Array_combine remove duplicate array    </p>
  
  <pre class="lang-php prettyprint-override"><code>    &lt;?php
          $a1=array("red","red");
          $a2=array("blue","yellow");
          print_r(array_combine($a1,$a2));
      ?&gt;
  </code></pre>
  
  <p>This code give output : <code>Array ( [red] =&gt; yellow )</code></p>
  
  <p>But I want output like this: <code>Array ( [red] =&gt; blue [red] =&gt; yellow )</code></p>