Comments on: Does a NSString contain a substring ?

By: Spencer MacDonald

Spencer MacDonald — Fri, 19 Feb 2010 19:51:46 +0000

Hi Susan

Something like the following (as a category on NSString):

- (BOOL)doesContainSubstring:(NSString *)substring{

//If self or substring have 0 length they cannot match
//This can have odd results with NSRange
if([self length] == 0 || [substring length] == 0)
return NO;

NSRange textRange;

textRange = [[self lowercaseString] rangeOfString:[substring lowercaseString]];

if(textRange.location != NSNotFound)
{
return YES;
}else{
return NO;
}

}

By: Susan

Susan — Fri, 19 Feb 2010 05:11:38 +0000

I’ll use that code A LOT.

How would I make it into a Category and just make it a part of NSString everywhere?

By: Robert

Robert — Tue, 09 Feb 2010 14:15:47 +0000

You posted this 10 months ago and it’s still helping people. Thanks for the information.

By: jose

jose — Sun, 20 Dec 2009 15:11:41 +0000

@frank, you need to chill dawg. just because you dont like (or know) something doesnt mean it sucks. different strokes for different folks.

By: Spencer MacDonald

Spencer MacDonald — Wed, 16 Sep 2009 18:34:56 +0000

To say it is a bit messed up is a bit extreme

Its different, and I expect a lot of people prefer it to C/C++, myself included.

By: frankSinatra

frankSinatra — Wed, 16 Sep 2009 18:01:00 +0000

crisbetewsky, pity!what pity! probably because Obj-C sucks big time. People in Apple are so stupid not to use just C/C++ instead of this messed up language obj-C. (-) (+) before function call waiting for some typos and headaches.

By: CrisBetewsky

CrisBetewsky — Mon, 06 Jul 2009 19:50:26 +0000

Some of us even don’t realize the importance of this information. What a pity.

By: KattyBlackyard

KattyBlackyard — Mon, 15 Jun 2009 05:58:12 +0000

Hi, very nice post. I have been wonder’n bout this issue,so thanks for posting

By: Spencer MacDonald

Spencer MacDonald — Sat, 30 May 2009 08:54:11 +0000

A very valid point Vincent.

For the people that are new to Objective-C it is important to mention that messages sent to an object that is nil, are simply ignored. But in the example above the rest of the code will still run with NSRange being undefined.

By: Vincent Gable

Vincent Gable — Fri, 29 May 2009 08:03:21 +0000

Unfortunately, if string is nil, then -rangeOfString: is going to give you an undefined value, especially on iPhone. You probably want to check that string != nil before calling -rangeOfString:. Here's more information on the problem. I'm always wary of methods that return a struct, like NSRange, because they are ill behaved if something is nil.