title: PHP Array_filter on "simple" multi-level array
body: <p>Can I and how can I use PHP's <code>array_filter</code> to filter the blank/nulls entries out of the following array structure?</p>
  
  <p><strong>From:</strong> The array is from a PDO call using Fetch BOTH so the numeric and named values are always equal in this case.</p>
  
  <pre><code>Array
  (
      [2400] =&gt; Array
          (
              [0] =&gt; Array
                  (
                      [value] =&gt; 7
                      [0] =&gt; 7
                  )
              [1] =&gt; Array
                  (
                      [value] =&gt; 61
                      [0] =&gt; 61
                  )
              [2] =&gt; Array
                  (
                      [value] =&gt; 42
                      [0] =&gt; 42
                  )
              [3] =&gt; Array
                  (
                      [value] =&gt; 
                      [0] =&gt; 
                  )
          )
  )
  </code></pre>
  
  <p><strong>To:</strong></p>
  
  <pre><code>Array
  (
      [2400] =&gt; Array
          (
              [0] =&gt; Array
                  (
                      [value] =&gt; 7
                      [0] =&gt; 7
                  )
              [1] =&gt; Array
                  (
                      [value] =&gt; 61
                      [0] =&gt; 61
                  )
              [2] =&gt; Array
                  (
                      [value] =&gt; 42
                      [0] =&gt; 42
                  )
          )
  )
  </code></pre>
  
  <p>I have tried </p>
  
  <ul>
  <li>plain old <code>array_filter</code></li>
  <li><code>array_filter(array, function($f){ ??? })</code> and not quite sure where to go from here... I was going to foreach the array to delve into it but how will that affect the entries through <code>array_filter</code>? Won't a true/false return bring in the entire [2400] array portion? It just has me confused.</li>
  </ul>
  
  <p>Please suggest improvements to the question</p>