Q:

Different between implementing two class in iphone

I want to know the difference between creating classes in iphone.
@interface classA (UIView){

}

@end

and 
@interface classA : UIView {

}

@end

Does anyone know the exact different between these two?
Thanks in advance

A:

The first block of code is used to create category. and second block is used to create classes in objective c. With the help of category you can add methods to the existing classes.

A:

Your first example would be wrong.
You would use the first one to create a category, and could be used like this:
@interface UISwitch (PrivateMethods)
-(void)setAlternateColors:(BOOL)alternateColors;
@end

Where as your second example is your own class:
@interface MyClass : UIView 
{ /* pointers */ }
@end

