title: Getting the index of a particular item in array
body: <p>I want to retrieve the index of an array but I know only a part of the actual value in the array.</p>
  <p>For example, I am storing an author name in the array dynamically say &quot;author = 'xyz'&quot;. <br/>
  Now I want to find the index of the array item containing it, since I don't know the value part.</p>
  <p>How to do this?</p>