Comments on: Evil: knowing when a method got passed the default value

By: Ben Goering

Ben Goering — Wed, 16 Apr 2008 23:00:19 +0000

What a fabulous way to humiliate fools!

Cool post, though. Even a ruby noob like me can understand it!

By: Chris Shea

Chris Shea — Sun, 13 Apr 2008 15:47:15 +0000

@João: The original problem was that I had a method that should take any object whatsoever and return something based on that, but return something else if the method wasn’t passed anything. A default value of nil wouldn’t help in that case, because the method was expected to handle nil just like everything else.

The solution I ended up with was to rethink my approach. But x=(x_not_given = true) could have worked.

By: João Paulo Lins

João Paulo Lins — Sun, 13 Apr 2008 15:16:09 +0000

I think to do conditional within method is best, because code is more legible and safe.However is like you said: “Use that at your own peril.”

def greet_world(salutation = nil)
salutation = salutation.nil? ? ‘Hello’ : salutation == ‘Hello’ ? ‘YOU HAVE NO IMAGINATION!’ : salutation
end

By: crayz

crayz — Sun, 13 Apr 2008 03:57:36 +0000

Wow, just wow. That is ridiculous, but I can actually see it coming in handy sometimes (e.g. maintaining backwards compatibility with an API that’s changing default values in a method call)

Very cool tip