Objective-C - Overriding method in subclass

Question

I am having some trouble figuring out hour to accurately override a method in one of my subclasses.

I have subclass (ClassB) of another customclass (ClassA):

@interface ClassB : ClassA { } 

and within ClassA, there is a method called:

-(void)methodName; 

which fires correctly.

However, I need this method to fire in ClassB.

I've tried implementing (in ClassB):

-(void)methodName {   [super methodName]; } 

but it still won't fire in ClassB.

How can I override methodName so that it will fire in ClassB?

Answer 1

You just add your custom code in methodName in classB :

- (void)methodName {     // custom code      // call through to parent class implementation, if you want     [super methodName]; } 

Answer 2

First, make sure your init method creates a ClassB object and not a ClassA (or something else) object.

Then, if you want to create a completely different classB (void)methodName: method than the one found in classA, this is the way to go:

Super is the superclass. By calling [super methodName] you're asking ClassA to execute it's own methodName. If you want to completely override methodName from classA, just don't call super.

So, basically, in your classB's implementation of methodName:

-(void)methodName {   // Remove [super methodName]   // Insert the code you want for methodName in ClassB } 

Feel free to read Messages to self and super in Apple's The Objective-C Programming Language document.