Question

In terms of memory management, is it correct to modify the input variable content in the following method?

- (NSMutableArray *) extractResults:(NSString *)content {
  ...
  regex = [NSRegularExpression ...];
  content = [regex stringByReplacingMatchesInString:content
                                            options:0
                                              range:NSMakeRange(0, [content length])
                                       withTemplate:@""];
  ...
}

In this particular case I do not care if the value remains modified outside the method scope. Just wondering if that assignment produces a memory leak.

Thanks!

Answer 1

No, it doesn’t produce a leak because the return value of stringByReplacing... is autoreleased. However, you should be aware that you are not modifying the content object at all. NSString is immutable, so you can’t do that, you’re creating a new instance and assigning it to the variable.