title: How to extract a portion of a string in c++?
body: <p>I have a string as below:</p>
  
  <pre><code>string str="university";
  </code></pre>
  
  <p>and i want to take a portion if this str like "versi" and save it to another string
  how do i do that?</p>
  
  <p>thanks.</p>