title: finding repeated value in objects inside an array in javascript
body: <p>have an array of data for example :</p>
  <p><code>const array=[{ a:&quot;cat&quot;}, { a:&quot;dog&quot;}, { a:&quot;dog&quot;},{ a:&quot;dog&quot;}]</code></p>
  <p>iterating over the array and looking for a logic to check the value of &quot; a &quot; to see if it is repeated or not, if repeated return only once otherwise return</p>