Split and remove duplicate from String
<p>I want to split the given string and remove the duplicate from that string. Like I have following string:</p>

<blockquote>
  <p>This is my first post in stack overflow, I am very new in development and I did not have much more idea about the how to post the question.</p>
</blockquote>

<p>Now I want to split that whole string with white space and that new array will did not have duplicate entry.</p>

<p>How can I do this?</p>
