Basically I have a Parent superclass which i.e is called MAMMAL. The mammal by default extends a UIImageview. Now I have tiger class which in turns extend the MAMMAL class and the mammal class has i.e a breastfeedbaby method.
In my mammal.h class, i declare the breastfeedbaby method.
Now , I want to be able to do something like adding a list of animals which extends mammal and have their own breastfeedbaby implementation, loop through and array and just cast to Mammal and do [mammal breastfeedbaby].
I would like each animal to call their own breastfeedbaby method since they all overide it but my issue is that it will call the breastfeedbaby from the mammal.m if i declare it there.
In java i can ei开发者_开发技巧ther use an interface or just have an abstract class with abstract method and have the different implementations override the method.
Does that make sense? My issue is that if i do not omit the breastfeedbaby method in mammal.m it will call the breastfeedbaby method in the mammal.m and if i do ommit the breastfeedbaby method in the mammal.m, the class will be yellow with warnings saying i did not implement the mammal.h class correctly. If I do that the animals' breastfeedbaby method is called. Should I just use a protocol here but from what I understand a protocol is not the same as an interface in java.
I don't know if it makes sense but thanks anyways.
Following scenario:
- Mammal.h:
- (void)method;
- Mammal.m:
- (void)method { NSLog(@"Mammal"); }
- Monkey.h:
@class Monkey : Mammal
- Monkey.m:
- (void)method { [super method]; NSLog(@"Monkey"); }
- Somewhere.m:
Mammal *monkey = [[Monkey alloc] init]; [monkey method];
Should yield:
Mammal
Monkey
UPDATE: of course, you can remove the call to [super method]
if you wish. Just showing the possibility.
Objective-C resolves everything dynamically, so it doesn't have abstract base classes or interfaces. The closest you can get to an abstract method is to write a default implementation (in the parent class) that throws an exception.
@implementation Mammal
- (void)breastfeedBaby
{
[NSException raise:@"MethodNotImplemented"
format:@"Class %@ failed to implement required method %@", NSStringFromClass([self class]), NSStringFromSelector(_cmd)];
}
@end
It would be nice to catch missing methods at compile-time, but that just isn't possible in a language with dynamic typing.
Even if you cast an object as a MAMMAL, it will still call the -breastfeedbaby
method for whatever subclass it is. This is because Objective-C uses message sending.
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