Java Inheritance:
Acquiring features from the
super class (parent class) to subclass(child class) in known as inheritance.
Inheritance follows IS-A
relationship, it is also known as parent to child relation.
By using of extends
keyword we can inherit super class into subclass.
Derived class: Derived class is also
known as child class (or) subclass.
Base class: In Java base class is
also known as parent class (or) super class.
In inheritance subclass has all properties of super class & subclass have extra properties.
Types of inheritance:
There are Five types of
inheritances in java.
1.Single inheritance
2.Multilevel inheritance
3.Multiple inheritance
4. Hierarchical inheritance
5. Hybrid Inheritance
When a class extends another
class is known as single inheritance. It containing single
base class and single derived class in the example manager class is a base
class(parent class) and Employee class is derived class(child class).
Example :
2. Multilevel inheritance:
In Multilevel
inheritance initially consisting one base class(parent
class) and one derived class(child class) and derived class(child class) act as
a base class to another class.
Example:Multilevel
inheritance
Initially HOD class act as a
parent class to student class.Principal class act as the parent class to HOD
class and now HOD class becomes child class to Principal class.
3.Multiple inheritance:
Java doesn’t support Multiple inheritance, because
of Diamond problem.
Multiple inheritance
consisting of one parent class and two child classes.
4. Hierarchical inheritance:
In Hierarchical
inheritance one parent class(base class) and two many child
classes(derived classes).
Example:
Mobile subscribers there is postpaid subscribers and prepaid subscribers.
5. Hybrid Inheritance:
Hybrid Inheritance is
a combination of both multiple inheritance and single inheritance. Java doesn’t
support Hybrid Inheritance but by using of Interface we can achieve this.
Example:
In Hybrid
Inheritance class A acting as a base class for class
B, class C(derived classes) and class B and class C acting
as a base class(parent
class) to class D(child class).
Syntax for inheritance:
Class child class extends parent class{
//methods
}
Advantages with inheritance:
1.Inheritance provides Code reusability.
2.By using inheritance we can achieve Run time polymorphism.
3. Method overriding.
Limitations:
1.Minimum two java classes are
required.
2.Handling complexity.
3.Multiple inheritance doesn't support
java.
4. Hybrid Inheritance
doesn't support java but by using the interface we can achieve.
5.Java extends only one class.
Interview Questions:
1.Explain about Java inheritance?
2.Is Java support multiple inheritance?
3.Limitations of inheritance?
4.Explain about oops concepts?
5.What is the relationship inheritance follows?
6.How many class can extend at a time in a Java class?
7.How can we achieve Hybrid inheritance?
8.Write syntax of inheritance?
9.Why do we need inheritance?
10.Why Java doesn't support multiple inheritance?
1.Explain about Java inheritance?
2.Is Java support multiple inheritance?
3.Limitations of inheritance?
4.Explain about oops concepts?
5.What is the relationship inheritance follows?
6.How many class can extend at a time in a Java class?
7.How can we achieve Hybrid inheritance?
8.Write syntax of inheritance?
9.Why do we need inheritance?
10.Why Java doesn't support multiple inheritance?
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