title: php getting unique values of a multidimensional array
body: <blockquote>
    <p><strong>Possible Duplicate:</strong><br>
    <a href="https://stackoverflow.com/questions/1861682/php-multi-dimensional-array-remove-duplicate">php multi-dimensional array remove duplicate</a>  </p>
  </blockquote>
  
  
  
  <p>I have an array like this:</p>
  
  <pre><code>$a = array ( 
      0 =&gt; array ( 'value' =&gt; 'America', ), 
      1 =&gt; array ( 'value' =&gt; 'England', ),  
      2 =&gt; array ( 'value' =&gt; 'Australia', ), 
      3 =&gt; array ( 'value' =&gt; 'America', ), 
      4 =&gt; array ( 'value' =&gt; 'England', ), 
      5 =&gt; array ( 'value' =&gt; 'Canada', ), 
  )
  </code></pre>
  
  <p>How can I remove the duplicate values so that I get this:</p>
  
  <pre><code>$a = array ( 
      0 =&gt; array ( 'value' =&gt; 'America', ), 
      1 =&gt; array ( 'value' =&gt; 'England', ),  
      2 =&gt; array ( 'value' =&gt; 'Australia', ), 
      4 =&gt; array ( 'value' =&gt; 'Canada', ), 
  )
  </code></pre>
  
  <p>I tried using array_unique, but that doesn't work due to this array being multidimensional, I think.</p>
  
  <p>Edit: I also need this array to be multi-dimensional and in this format, I can't flatten it.</p>