String compare in iOS

I want to find out whether a given NSString or CFStringRef contai开发者_StackOverflowns a certain substring. How do I do that?

- (NSRange)rangeOfString:(NSString *)aString

...is your man. For example:

NSString* search = @"Where's the manual?";
NSRange range = [search rangeOfString: @"the"];
NSLog( @"Found at %u", range.location );

Please read the NSString class reference. What you want is pathExtension.