title: String find and replace
body: <p>I have a string like</p>
  
  <pre><code>string text="~aaa~bbb~ccc~bbbddd";
  </code></pre>
  
  <p>The input value will be : <strong>bbb</strong></p>
  
  <p>So in the above string i should remove the value <strong>"~bbb"</strong></p>
  
  <p>The resulting string should be</p>
  
  <pre><code>text="~aaa~ccc~bbbddd";
  </code></pre>