title: Convert multidimensional array into single array
body: <p>I have an array which is multidimensional for no reason</p>
  
  <pre><code>/* This is how my array is currently */
  Array
  (
  [0] =&gt; Array
      (
          [0] =&gt; Array
              (
                  [plan] =&gt; basic
              )
  
          [1] =&gt; Array
              (
                  [plan] =&gt; small
              )
  
          [2] =&gt; Array
              (
                  [plan] =&gt; novice
              )
  
          [3] =&gt; Array
              (
                  [plan] =&gt; professional
              )
  
          [4] =&gt; Array
              (
                  [plan] =&gt; master
              )
  
          [5] =&gt; Array
              (
                  [plan] =&gt; promo
              )
  
          [6] =&gt; Array
              (
                  [plan] =&gt; newplan
              )
  
      )
  
   )
  </code></pre>
  
  <p>I want to convert this array into this form</p>
  
  <pre><code>/*Now, I want to simply it down to this*/
  Array (
  [0] =&gt; basic
  [1] =&gt; small
  [2] =&gt; novice
  [3] =&gt; professional
  [4] =&gt; master
  [5] =&gt; promo
  [6] =&gt; newplan
  )
  </code></pre>
  
  <p>Any idea how to do this? </p>