title: Unset index of an array inside another array
body: <p>I have an array with in which there is another array. I need to unset a index of the sub array.</p>
  
  <pre><code>array
    0 =&gt; 
      array
        'country_id' =&gt; string '1' (length=1)
        'description' =&gt; string 'test' (length=4)
    1 =&gt; 
      array
        'country_id' =&gt; string '2' (length=1)
        'description' =&gt; string 'sel' (length=5)
    2 =&gt; 
      array
        'country_id' =&gt; string '3' (length=1)
        'description' =&gt; string 'soul' (length=5)
  </code></pre>
  
  <p>Now i need to unset <code>country_id</code> of all the three index of the master array. I am using PHP and I initially thought unset will do until i realized my array is nested.</p>
  
  <p>How can I do this?</p>