I just ran the following as a test
NSString * myString = @"Hello,";
NSString * newString = [myString stringByReplacingOccurrencesOfString:@"," withString:@""];
NSLog(@"%@xx",newString);
And I get 2010-04-05 18:51:18.885 TestString[6823:a0f] Helloxx
as output. There is no space left.