title: Importance of a singlecolon ":" in C++
body: <blockquote>
    <p><strong>Possible Duplicate:</strong><br>
    <a href="https://stackoverflow.com/questions/1711990/what-is-this-weird-colon-member-syntax-in-the-constructor">What is this weird colon-member syntax in the constructor?</a>  </p>
  </blockquote>
  
  
  
  <p>Rarely in the regular codes I encounter the a single colon in classes
  for e.g.:</p>
  
  <pre><code>A::member():b(),c()
  {
  }
  </code></pre>
  
  <p>What is the importance of the single colon over here? Why is it used here?
  Is it mandatory sometimes? If so in which cases?</p>