title: Use delegate in place of interface
body: <p>I read that you can use interfaces and delegates for the same purpose. Like, you can use delegates instead of interfaces.</p>
  
  <p>Can someone provide an example? I've seen an example in the nutshell book but I fail to remember and wanted to ask away.</p>
  
  <p><strong>Is it possible to provide some sample code? Use case?</strong></p>
  
  <p>Thanks.</p>