Question

I am getting NSCFString for the code below:

NSString *urlString;

/*  leak showing below line */

urlString = [urlString stringByReplacingOccurrencesOfString:@"\n" withString:@""];

How do you solve this leak?

Answer 1

Most likely you created your urlString using +alloc/initWith.... If that’s the case then you own the urlString reference and are responsible for releasing it at some point. However, when you get to the line you pasted in the question, you’re overwriting the urlString reference with a new string reference, since stringByReplacingOccurrencesOfString:withString: returns a new string object (ie, it doesn’t modify the string in place).

My recommendation would be to use an NSMutableString instead, which does allow in-place string manipulation.