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Inheritance-4

Example10:-


class Student
{
Student()
{
System.out.println("This is super class Zero argument constructor");
}
Student(String s)
{
System.out.println("This is super class One argument constructor");
}
}
class Test extends Student
{
Test()
{
super(null);
System.out.println("This is sub class Zero argument constructor");
}
public static void main(String[]args)
{
Test t=new Test();
}
}

Output:-

C:\JAVATECH>javac Test.java
C:\JAVATECH>java Test

This is super class One argument constructor
This is sub class Zero argument constructor

Example11:-


class Student
{
Student()
{
System.out.println("This is super class Zero argument constructor");
}
Student(String s)
{
System.out.println("This is super class One argument constructor");
}
}
class Test extends Student
{
Test()
{
super();
super(null);
System.out.println("This is sub class Zero argument constructor");
}
public static void main(String[]args)
{
Test t=new Test();
}
}

Output:-

C:\JAVATECH>javac Test.java

Test.java:17: error: call to super must be first statement in constructor
super(null);
     ^
1 error


Example12:-


class Student
{
Student()
{
System.out.println("This is super class Zero argument constructor");
}
Student(String s)
{
System.out.println("This is super class One argument constructor");
}
}
class Test extends Student
{
Test()
{
System.out.println("This is sub class Zero argument constructor");
}
Test(String s)
{
System.out.println("This is sub class One argument constructor");
}
public static void main(String[]args)
{
Test t1=new Test();
Test t2=new Test(null);
}
}

Output:-

C:\JAVATECH>javac Test.java
C:\JAVATECH>java Test

This is super class Zero argument constructor
This is sub class Zero argument constructor
This is super class Zero argument constructor
This is sub class One argument constructor


Example:-13


class Student
{
Student()
{
System.out.println("This is super class Zero argument constructor");
}
Student(String s)
{
System.out.println("This is super class One argument constructor");
}
}
class Test extends Student
{
Test()
{
super(null);
System.out.println("This is sub class Zero argument constructor");
}
Test(String s)
{
super(null);
System.out.println("This is sub class One argument constructor");
}
public static void main(String[]args)
{
Test t1=new Test();
Test t2=new Test(null);
}
}

Output:-

C:\JAVATECH>javac Test.java
C:\JAVATECH>java Test

This is super class One argument constructor
This is sub class Zero argument constructor
This is super class One argument constructor
This is sub class One argument constructor


Multilevel inheritance: - Multilevel inheritance is a collection of single inheritance or collection of more single inheritance.

class A{}
class B extends A{}
class C extends B{}
or
class A{}
class B extends A{}
class C extends B{}
class D extends C{}


Example14:-


class A
{
void A()
{
System.out.println("A class Method");
}
}
class B extends A
{
void B()
{
System.out.println("B class Method");
}
}
class C extends B
{
void C()
{
System.out.println("C class Method");
}
}
class Test
{
public static void main(String[]args)
{
C object=new C();
object.A();
object.B();
object.C();
}
}

Output:-

C:\JAVATECH>javac Test.java
C:\JAVATECH>java Test

A class Method
B class Method
C class Method


Example15:-


class A
{
int a;
}
class B extends A
{
int b;
}
class C extends B
{
void setData()
{
a=10;
b=100;
}
void getData()
{
System.out.println("sum="+(a+b));
}
}
class Test
{
public static void main(String[]args)
{
C object=new C();
object.setData();
object.getData();
}
}

Output:-

C:\JAVATECH>javac Test.java
C:\JAVATECH>java Test

sum=110



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