CODEWITHSUNDEEP
iosinheritance
Prez
Prez

Reputation: 227

Inheritance supported by objective c

Hi I am a newbie in objective c.I am going through the concepts of inheritance in objective c.On reading a tutorial on tutorials point.I found that objective C supports multilevel inheritance.But whatever I have implemented now it appears that objective c supports Hierarchical inheritance also.As we can see in the following code:

@interface Shape : NSObject

{
    CGFloat area;
}
@end

@interface Square : Shape
{
    CGFloat length;
}
@end

@interface Rectangle : Shape
{
    CGFloat length;
    CGFloat breadth;
}
 @end

In such situation,Please help me to understand now the type of inheritances supported by objective c

Upvotes: 2

Views: 697

Answers (2)

Duncan C
Duncan C

Reputation: 131418

Multi-level inheritance is where you have several generations of classes:

@interface Shape : NSObject
{
    CGFloat area;
}
@end

@interface Rectangle : Shape
{
    CGFloat length;
    CGFloat breadth;
}
@end

@interface Square : Rectangle
{
}
@end

In the example above, the base class is shape. A Rectangle is a type of Shape, and a Square is a type of Rectangle. The Rectangle's parent class is Shape. The Square's parent class is Rectangle, and it's "grandparent" class is Shape. (Squares are a special type of rectangle). A square doesn't need any extra properties. In fact it needs less properties than a rectangle.)

Hierarchical inheritance is where a parent class has more than one child class. For example, a shape class might have child classes of Rectangle, Circle, and Triangle.

Objective-C supports both types of inheritance.

Multiple inheritance is a different thing. That's where a class can inherit traits from multiple parents. Objective-C does not support multiple inheritance. Neither does Swift or Java for that matter.

(BTW the terms multi-level inheritance and hierarchical inheritance are not widely used in the industry. I had to look them up on Wikipedia in order to understand the distinction. I can't think of an object-oriented language that does not support both multi-level inheritance and hierarchical inheritance.)

Upvotes: 0

Tabz
Tabz

Reputation: 172

Objective c doesn't support multiple inheritance. You can refer this link Objective C programming guide

Though you can mimic the functionality of multiple inheritance using protocols but there is no official support for multiple inheritance in objective c.

Upvotes: 1

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