"GOTO Death & Slaughter"

We recently had an internal discussion concerning the use of GOTO's in code and its
implications. I was reminded of a great paper by Djikstra on the subject... it's a
quick and great read: https://www.acm.org/classics/oct95/.

For those of you who consider the title of this posting slightly
odd, please keep in mind that I've now seen Pirates of Penzance 4 times in the past
few weeks. Fantastic show!

Comments

• Anonymous
  March 23, 2004
  I feel slightly guilty even when I throw too many exceptions. I sometime write code like:
  
  if (somethingBad)
  throw new ApplicationException("Something bad.");
  else
  {
  //do something
  }
  
  to make it clearer that there's a program flow change, but I've developed a bad habit of writing stuff like:
  
  if (somethingBad)
  throw new ApplicationException("Something bad.");
  
  //do something
  
  What are your thoughts on minimizing the impact of Exception handling on the ability to easily interpret code flow?
• Anonymous
  March 25, 2004
  I don't think there's a major difference between the two examples you've posted, mainly because of their simplicity (one if statement resulting in possibly throwing one exception). Personally, in most situations where this arises I prefer the latter as it is easier to read and does the exact same thing; in fact, the MSIL generated for each by the C# compiler will be exactly the same.
  
  Guard statements are often used as in the latter case to handle parameter checking in functions. This makes it clean to write code like:
  
  if (param1 == null) throw new ArgumentNullException("param1");
  if (param2 == null) throw new ArgumentNullException("param2");
  if (param3 == null) throw new ArgumentNullException("param3");
  // now do work of method
  
  I'd find it annoying to read that same code written as:
  
  if (param1 == null)
  {
  throw new ArgumentNullException("param1");
  }
  else
  {
  if (param2 == null)
  {
  throw new ArgumentNullException("param2");
  }
  else
  {
  if (param3 == null)
  {
  throw new ArgumentNullException("param3");
  }
  else
  {
  // now do work of method
  }
  }
  
  I think the guard statements make the code flow much easier to understand.
  
• Anonymous
  June 17, 2009
  PingBack from http://pooltoysite.info/story.php?id=2645