Skip to main content

Inheritance in java

 Introduction


    If the one object can acquires all the properties and behaviour of parent object then it's called Inheritance. The idea behind inheritance concept is, we can create a new class which is build upon existing one so we can reuse the methods and field of the parent class and also create new method in child class. Inheritance is use for method overriding and code reusability concepts. To create new child class from parent class we use the extends keyword. Syntax of define inheritace is as follow:

class ChildClass extends ParentClass{
    variable declaration;
    method declaration;
}

There are different types of inheritance in java as follows:

  1. Single Inheritance.
  2. Multilevel Inheritance.
  3. Hierarchical Inheritance.


1. Single Inheritance:

    A class/parent class inherits another class/child class is called Single inheritance. For example,

class Animal{  

void eat(){System.out.println("eating...");}  

}  

class Dog extends Animal{  

void bark(){System.out.println("barking...");}  

}  

public class Single {

public static void main(String[] args) {

Dog d=new Dog();  

d.bark();  

d.eat();  

}

}

OUTPUT:

barking...

eating...


2. Multiple Inheritance:

    A chain of inheritance is called as Multiple inheritance.  For example, 

class Animal1{  

void eat(){System.out.println("eating...");}  

}  

class Dog1 extends Animal1{  

void bark(){System.out.println("barking...");}  

}  

class BabyDog extends Dog1{  

void weep(){System.out.println("weeping...");}  

}  

public class Multilevel {

public static void main(String[] args) {

BabyDog d=new BabyDog();  

d.weep();  

d.bark();  

d.eat(); 

}

}

OUTPUT:
weeping...
barking...
eating...

3. Hierarchical Inheritance:

    A two or more classes inherits a single class then it's called hierarchical inheritance. For example,

class Animal2{  

void eat(){System.out.println("eating...");}  

}  

class Dog2 extends Animal2{  

void bark(){System.out.println("barking...");}  

}  

class Cat extends Animal2{  

void meow(){System.out.println("meowing...");}  

}  

public class Hierarchical {

public static void main(String[] args) {

Cat c=new Cat();  

c.meow();  

c.eat();  

//c.bark();//C.T.Error  

}

}

OUTPUT:

meowing...

eating...


Labels:

Comments

Post a Comment

Popular posts from this blog

Introduction of Java

 What is Java? Java is an object-oriented programming language developed by Sun Microsystem in 1995. It is a combination of C and C++ features with some essential and additional concepts. Java is suited for both standalone and web application development. Java can run on any hardware OR software environment which make it platform independent. Java Example:                                                                                           class Simple{     public static void main(String args[]){          System.out.println("Welcome In Java World");     } } In above example the 'Simple' is a Class name, public is access specifier , Main is a method with argument, St...
Post a Comment
Read more

Decision Making and Branching Statements / Control Statements

 Introduction     Java is a set of statements which executed sequentially in the order in which they appear. This will happen when option or repetitions of certains are not necessary. However, We have a number of situation, where we may have to change the order of execution of statement on bases of certain conditions. This involves a kind of dicision making to see the particular condition occured or not and the direction of execution will execute according to it.     When program braks the sequential flow and jump on the another part of code then it's called branching . When branching is on particular condition then it's called conditional branching . If branches executes without any particular conditions then it's call unconditional branching .     Java supports such decision making capabilities and supports following statements known as Control statement or Decision making statement .     if statements     switch statement   ...
Post a Comment
Read more

Access Modifiers in Java

 Introduction There are two types of modifiers in Java: access modifiers and non-access modifiers. The access modifiers in Java specifies the accessibility or scope of a field, method, constructor, or class. We can change the access level of fields, constructors, methods, and class by applying the access modifier on it. There are four types of Java access modifiers: 1. Private: The access level of a private modifier is only within the class. It cannot be accessed from outside the class. 2. Default: The access level of a default modifier is only within the package. It cannot be accessed from outside the package. If you do not specify any access level, it will be the default. 3. Protected: The access level of a protected modifier is within the package and outside the package through child class. If you do not make the child class, it cannot be accessed from outside the package. 4. Public: The access level of a public modifier is everywhere. It can be accessed from within the clas...
Post a Comment
Read more