Can someone please explain this Objective-C syntax?

Question

I'm having trouble making sense of the following:

UILabel *label = (UILabel *)[cell viewWithTag:1000];

I understand that UILabel is a class. So we're creating a pointer named *label that points to an instance of UILabel.

Right of the equals sign, I understand that [cell viewWithTag:1000]; is passing cell a method named viewWithTag with the argument 1000.

What does the (UILabel *) before that mean?

It isn't passing a method; it's sending a message. Passing a method is a different and quite specific idea. — Marcelo Cantos
– Marcelo Cantos, Commented Feb 7, 2012 at 21:46
Sorry, coming from other OO languages and still getting my head around the terminology. — bodacious
– bodacious, Commented Feb 7, 2012 at 21:54

Dan F · Accepted Answer · 2012-02-07 21:37:34Z

2

It means to cast the object type to a UILabel*. By default, viewWithTag: returns a UIView*

answered Feb 7, 2012 at 21:37

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Comments

Peter Kelly · Accepted Answer · 2012-02-07 21:49:50Z

It is casting the result to a UILabel. The syntax is the same as in C - (Objective-C is a super-set of C).

You can also check the type before using it (although not really necessary if you are confident of what is being returned) using isKindOfClass