title: remove specific characters from NSString
body: <p>I wants to remove specific characters or group substring from NSString.</p>
  
  <p>mean</p>
  
  <p>NSString *str = @" <strong>hello I am #39;doing Parsing  So $#39;I get many symbols in &amp;my response</strong>";</p>
  
  <p>I wants remove #39;      and     $#39; and &amp;   (Mostly these three strings comes in response)</p>
  
  <p><strong>output should be :</strong> hello I am doing Parsing So i get many symbols in my response</p>
  
  <p>Side Question : I can't write &amp; #39; without space here, because it converted in &#39; &lt;-- this symbol. so i use $ in place of &amp; in my question. </p>