title: Array merge not merging one element
body: <p><strong>Array 1</strong> : <code>$gpsArr</code></p>
  
  <pre><code>Array
  (
      [store_id] =&gt; Array
          (
              [0] =&gt; 101
          )
  
      [store_name] =&gt; Array
          (
              [0] =&gt; Out of the Blue - Powai
          )
  
      [store_logo] =&gt; Array
          (
              [0] =&gt; /Out-of-the-Blue-Powai.jpg
          )
  
      [deals_image] =&gt; Array
          (
              [0] =&gt; 
          )
  
  )
  </code></pre>
  
  <p><strong>Array 2</strong> : <code>$dataArr</code></p>
  
  <pre><code>Array
  (
      [store_id] =&gt; Array
          (
              [0] =&gt; 87
              [1] =&gt; 88
              [2] =&gt; 99
              [3] =&gt; 100
          )
  
      [store_name] =&gt; Array
          (
              [0] =&gt; The Barking Deer Brewpub
              [1] =&gt; The Den
              [2] =&gt; Mini Punjab's Chinese Court
              [3] =&gt; Out of the Blue - Khar
          )
  
      [store_logo] =&gt; Array
          (
              [0] =&gt; /The-barking-deer-brewpub.png
              [1] =&gt; /the-den.png
              [2] =&gt; /Mini-Punjabs-Chinese-Court-Bandra.png
              [3] =&gt; /Out-of-the-Blue-Khar.jpg
          )
  
      [deals_image] =&gt; Array
          (
              [0] =&gt; the-barking-deer-brewpub-thumb297.jpg
              [1] =&gt; the-den-thumb297.jpg
              [2] =&gt; mini-punjub-chinese-court-thumb297.jpg
              [3] =&gt; out-of-the-blue-Khar-thumb297.jpg
          )
  
  )
  </code></pre>
  
  <p>By merging above two array using following code :</p>
  
  <pre><code>$result = array_unique(array_merge($gpsArr,$dataArr), SORT_REGULAR);
  </code></pre>
  
  <p>return following result :</p>
  
  <pre><code>Array
  (
      [store_id] =&gt; Array
          (
              [0] =&gt; 87
              [1] =&gt; 88
              [2] =&gt; 99
              [3] =&gt; 100
          )
  
      [store_name] =&gt; Array
          (
              [0] =&gt; The Barking Deer Brewpub
              [1] =&gt; The Den
              [2] =&gt; Mini Punjab's Chinese Court
              [3] =&gt; Out of the Blue - Khar
          )
  
      [store_logo] =&gt; Array
          (
              [0] =&gt; /The-barking-deer-brewpub.png
              [1] =&gt; /the-den.png
              [2] =&gt; /Mini-Punjabs-Chinese-Court-Bandra.png
              [3] =&gt; /Out-of-the-Blue-Khar.jpg
          )
  
      [deals_image] =&gt; Array
          (
              [0] =&gt; the-barking-deer-brewpub-thumb297.jpg
              [1] =&gt; the-den-thumb297.jpg
              [2] =&gt; mini-punjub-chinese-court-thumb297.jpg
              [3] =&gt; out-of-the-blue-Khar-thumb297.jpg
          )
  
  )
  </code></pre>
  
  <p>As you can see <code>store_id = 101</code> is not displayed after merging the array. Why this is happening? I think I done something silly thing but can you please tell me what I did wrong?</p>
  
  <p>Thanks in advance.</p>