Question

After some research, I can’t find anything on super classes, so I decided to ask here.

Example

@interface superClass : CCSprite
@end

@interface subClass : superClass
@end

How do the two above examples relate to each other? Also, I was shown that you could add a method the the superClass, and then use it in the subClass (how?)?

Answer 1

CCSprite is the super class of superClass
superClass is the super class of subClass

there is two ways of using method in super class, for example

@interface superClass : CCSprite
- (void)doSomething;
- (id)somethingElse;
@end

@implement superClass
- (void)doSomething {
    NSLog( @"do something in super class" );
}
- (id)somethingElse {
    return @"something else in super class";
}
@end

@interface subClass : superClass
- (void)doSomethingTwice;
@end
@implement subClass
- (void)doSomethingTwice {
    [self doSomething];
    [self doSomething];
}
- (id)somethingElse {
    id fromSuper = [super somethingElse];
    return @"something else in sub class";
}
@end

---

subClass sub = [[subClass alloc] init];
[sub doSomethingTwice];   // this will call `doSomething` implemented is superClass twice
NSLog([sub somethingElse]); // this will call `somethingElse` in super class but return "something else in sub class" because it override it

---

basically you can just call the method implemented in super class on instance of sub class

and you can override the method in sub class to do something different and/or using [super methodName] to call the method implementation in super class