title: Javascript - Merge two dimensional array with unique result
body: <p>I have this two array in Javascript</p>
  
  <pre><code>var array1 = [
                ["Tech &amp; Digital", 124],
                ["Stationery", 100]
               ]
  var array2 = [
                ["Gift Item", 125],
                ["Stationery", 100]
               ]
  </code></pre>
  
  <p>I want to merge this 2 array with unique value as follows,</p>
  
  <pre><code>            [
                ["Tech &amp; Digital", 124],
                ["Stationery", 100],
                ["Gift Item", 125]
               ]
  </code></pre>
  
  <p>I tried <code>concat</code> function, but it's not working as expected.</p>