Question

I can use the following codes to trim a string:

-(void) aMethod {
// myStr from a text box
NSString *trimedStr = [mystr stringByTrimmingCharactersInSet:
  [NSCharacterSet whitespaceAndNewlineCharacterSet]];
...
// should I release trimedStr?
}

Not sure if the result trimedStr is an autorelease string? How can I find out that?

Answer 1

The fundamental rule of memory management in Objective-C

You take ownership of an object if you
create it using a method whose name
begins with “alloc” or “new” or
contains “copy” (for example, alloc,
newObject, or mutableCopy), or if you
send it a retain message. You are
responsible for relinquishing
ownership of objects you own using
release or autorelease. Any other time
you receive an object, you must not
release it.

Since the name does not start with alloc or new and does not contain copy, it is autoreleased.