title: Tell if a Javascript function is defined by looking at self[name] - is this a good way?
body: <p>This is a follow up question to <a href="https://stackoverflow.com/questions/85815/how-to-tell-if-a-javascript-function-is-defined">This Question</a>. </p>
  
  <p>I like (and understand) the solution there. However, in the code I am working in, another way to solve the same problem is used:</p>
  
  <pre><code>function exist(sFN) {
      if(self[sFN]) return true;
      return false;
  }
  </code></pre>
  
  <p>It seems to work fine, although I don't understand how. Does it work? How? What are minuses of this approach? Should I switch to solution from the other question?</p>