Question

What is the defference if I called

NSString *theNameToDisplay = _name;

or

NSString *theNameToDisplay = self.name;

I know it might be a silly question but I see both versions used a lot and I don’t spot a difference in the output?

Thanks!

Answer 1

Assume you have in your .m file this line (and don’t have any overriden methods to direct access to _name)

@synthesize name = _name;

It mean that property name (self.name) will use variable _name when you try to access it. In this case self.name is equal to _name

---

But if you have dynamic property for name, something like this :

-(NSString)name{
    return @"1234";
}

then there is a difference. self.name will always return 1234, but _name can be not equal to this value.

Example:

_name = @"555";
NSLog(_name);
NSLog(self.name);

Result:

2012-02-09 14:27:49.931 ExampleApp[803:207] 555
2012-02-09 14:27:49.933 ExampleApp[803:207] 1234