title: "Is a" vs "Has a" : which one is better?
body: <p>Portfolio A → Fund 1</p>
  
  <p>Portfolio A → Fund 2</p>
  
  <p>Portfolio A → Fund 3</p>
  
  <p>I couldn't frame my sentence without not using is/has. But between 1 &amp; 2,</p>
  
  <p>1) has a:</p>
  
  <pre><code>class PortfolioA
  {
      List&lt;Fund&gt; obj;
  }
  </code></pre>
  
  <p>2) is a:</p>
  
  <pre><code>class PortfolioA : List&lt;Fund&gt;
  {
  
  }
  </code></pre>
  
  <p>which one do you think is better from the point of extensibility, usability? I can still access my funds either way, albeit with a small syntactical change.</p>