b) ) Write Java code for inserting the following

numbers 1, 2, 3, 4 into i) an Array, and ii) a ArrayList

c) What is the output of the following program.

public class Test

{

public static void main(String args[])

{ StringBuffer sb = new StringBuffer("abcdef");

sb.replace(0, 3, "xyz");

System.out.println(sb);

sb = new StringBuffer("abcdef");

sb.replace(sb.indexOf("abc"), sb.indexOf("def"), "lmo");

System.out.println(sb); }

}

d)

public interface Once{

public void sayItOnce(); }

public interface Twice{

public void sayItTwice(); }

public class A implements Once {

public void one() {

System.out.println( "A.1" ); }

public void two(){

one();

System.out.println( "A.2" ); }

public void sayItOnce() {

System.out.println("Ill say this once"); }

}

public class B extends A implements Once, Twice

{

public void one( int x){

System.out.println( "B.1 " + x ); }

public void two() {

System.out.println( "B.2" ); }

public void sayItTwice() {

System.out.println("Ill say this twice "); }

}

public class C extends A

{

public void one() {

System.out.println( "C.1" ); }

}

If the following pieces of code were to appear in a control program that used the classes A,B and C what would be the outputs

i)

A a = new B();

a.two();

ii)

B b = new B();

b.one(4);

b.one();

iii)

Once r = new B();

r.sayItOnce();

iv)

Twice b = new Twice();

b.sayItTwice();

v)

C c = new A();

c.two();

vi)

A a = new B();

a.sayItTwice() ;

vii)

A a = new C();

a.two();