Q 1) Write a Java program to demonstrate Nested Class.
Ans) {File name: Innerclassdemo.java}
class Outer
{
int outer_x=50;
void test()
{
Inner inner=new Inner();
inner.display();
}
class Inner
{
void display()
{
System.out.println("Display : outer_x =" +outer_x);
}
}
}
class Innerclassdemo
{
public static void main(String args[])
{
Outer outer = new Outer();
outer.test();
}
}
Q2) Write a java program to demonstrate Inheritance
Ans) {File name: inheritance_class.java}
class sup_class
{
int x,y;
void display()
{
System.out.println("X & Y : " +x+" "+y);
}
}
class sub_class extends sup_class
{
int z;
void show()
{
System.out.println("Z : "+z);
}
void multi()
{
System.out.println("X * Y * Z : "+(x*y*z));
}
}
class inheritance_class
{
public static void main(String args[])
{
sup_class sup=new sup_class();
sub_class sub=new sub_class();
sup.x=5;sup.y=10;
System.out.println("Contents of Sup Object : ");
sup.display();
System.out.println();
sub.x=3;
sub.y=7;
sub.z=8;
System.out.println("Contents of sub object : ");
sub.display();
sub.show();
System.out.println();
System.out.println("X * Y * Z in sub Object : ");
sub.multi();
}
}
Q3)Write a Java program to show the use of static block, method and variables
Ans) Prog 1 {File name: use static.java}
class usestatic
{
static int a=3;
static int b;
static void xab(int x)
{
System.out.println("x= "+x);
System.out.println("a= "+a);
System.out.println("b= "+b);
}
static {
System.out.println("Static block initiated");
b=a*4;
}
public static void main(String args[])
{
xab(50);
}
}
Prog 2) {File name: staticbyname.java}
class staticdemo
{
static int a=40;
static int b=90;
static void xyz()
{
System.out.println("a= "+a);
}
}
class staticbyname
{
public static void main(String[] args)
{
staticdemo.xyz();
System.out.println("b= " + staticdemo.b);
}
}
Q4) Write a Java program of method overriding where the method show() is overriden in both (super & sub) the classes.
Ans) {File name: override.java}
class A
{
int i,j;
A(int a, int b)
{
i=a; j=b;
}
void show()
{
System.out.println("i and j are: " +i+" "+j);
}
}
class B extends A
{
int k;
B(int a, int b, int c)
{
super(a,b);
k=c;
}
void show()
{
System.out.println("K : " +k);
}
}
class override
{
public static void main(String args[])
{
B subob=new B(1,2,3);
subob.show();
}
}
Q5) Write a Java program to access the superclass version of an overriding function.
Ans) {File name: override2.java}
class A
{
int i,j;
A(int a, int b)
{
i=a; j=b;
}
void show()
{
System.out.println("i and j are: " +i+" "+j);
}
}
class B extends A
{
int k;
B(int a, int b, int c)
{
super(a,b);
k=c;
}
void show()
{
super.show();
System.out.println("K : " +k);
}
}
class override2
{
public static void main(String args[])
{
B subob=new B(1,2,3);
subob.show();
}
}
Q6) Write a Java program to create a book shelve class and chair class by inheriting the furniture class.
Ans) {File name: inherit.java}
class furniture
{
String color,type;
void accept(String x, String y)
{
color=x; type=y;
System.out.println("The color is: " + color);
System.out.println("The type is: "+ type);
}
}
class book_shelves extends furniture
{
int no_shelves;
void item()
{
System.out.println("Book Shelves");
}
void display(int sh)
{
no_shelves=sh;
System.out.println("The number of shelves are: "+ no_shelves);
}
}
class chair extends furniture
{
int legs;
void item()
{
System.out.println("Chair");
}
void display(int l)
{
legs=l;
System.out.println("The legs are : "+legs);
}
}
class inherit
{
public static void main(String args[])
{
furniture f=new furniture();
book_shelves bs=new book_shelves();
chair ch=new chair();
bs.item();
bs.display(6);
System.out.println();
ch.item();
ch.accept("Yellow", "Steel");
ch.display(4);
}
}
Q7) Write a Java program to show the methods (same function name) with different type signatures are overloaded not overrides.
Ans) {File name: override3.java}
class A
{
int i,j;
A(int a, int b)
{
i=a; j=b;
}
void show()
{
System.out.println("i and j are: " +i+" "+j);
}
}
class B extends A
{
int k;
B(int a, int b, int c)
{
super(a,b);
k=c;
}
void show(String msg)
{
System.out.println(msg +k);
}
}
class override3
{
public static void main(String args[])
{
B subob=new B(1,2,3);
subob.show("This is K : ");
}
}
Q8) Write a Java program to implement run-time polymorphism.
Ans) {File name: dispatch.java}
class A
{
void callme()
{
System.out.println("Inside A's callme()");
}
}
class B extends A
{
void callme()
{
System.out.println("Inside B's callme()");
}
}
class C extends A
{
void callme()
{
System.out.println("Inside C's callme()");
}
}
class dispatch
{
public static void main(String args[])
{
A a= new A();
B b= new B();
C c=new C();
A r;
r=a;
r.callme();
r=b;
r.callme();
r=c;
r.callme();
}
}
