Re: argument checks
Re: argument checks
- Subject: Re: argument checks
- From: Adam Leonard <email@hidden>
- Date: Wed, 11 Jun 2008 23:07:54 -0700
Yeah, variables you declare in a method (not as instance variables)
are not automatically initialized to 0/NULL/nil for you.
If you try to use an uninitialized variable, it might point to some
left over object in memory, or it might map to nothing at all. It is
totally random.
What is the problem with just doing NSNumber *myNum = nil; ?
You can reassign it to a usable NSNumber object later, and if you
don't, checking for equality with nil (or just doing if(!myNum) ) will
let you catch that error.
Or am I missing something in your question....
Adam Leonard
On Jun 11, 2008, at 10:50 PM, Ashley Perrien wrote:
Noob question: I'm putting together a small code library and I'm
trying to include some error checking in the methods; what I want to
protect against is the following:
NSNumber *myNum;
// Lots of code where I've forgotten to actually do anything with
myNum
results = [myClass someCalculationUsing: myNum];
myNum in this case is an object and does exist but it's not a valid,
usable argument. So in the implementation I'd like to have something
along the lines of:
if (myNum == nil)
NSLog(@"some error message");
but can't figure out what to check for that would get me into the
error message condition. Any suggestions?
Ashley Perrien
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