title: How to sum all column values in multi-dimensional array?
body: <p>How can I add all the columnar values by associative key? Note that key sets are dynamic.  </p>
  
  <p>Input array:</p>
  
  <pre class="lang-none prettyprint-override"><code>Array
  (
      [0] =&gt; Array
          (
              [gozhi] =&gt; 2
              [uzorong] =&gt; 1
              [ngangla] =&gt; 4
              [langthel] =&gt; 5
          )
  
      [1] =&gt; Array
          (
              [gozhi] =&gt; 5
              [uzorong] =&gt; 0
              [ngangla] =&gt; 3
              [langthel] =&gt; 2
          )
  
      [2] =&gt; Array
          (
              [gozhi] =&gt; 3
              [uzorong] =&gt; 0
              [ngangla] =&gt; 1
              [langthel] =&gt; 3
          )
  )
  </code></pre>
  
  <p>Desired result:</p>
  
  <pre class="lang-none prettyprint-override"><code>Array
  (
      [gozhi] =&gt; 10
      [uzorong] =&gt; 1
      [ngangla] =&gt; 8
      [langthel] =&gt; 10
  )
  </code></pre>