Advance Java Lab MCQ

1. What is the output of this program?

import java.util.ArrayList;

public class ArrayListExample

{

    public static void main(String a[])

    {

        ArrayList<String> al = new ArrayList<String>();

        al.add(10);

        al.add(15);

        al.add(20);

        al.add(25);

        Iterator it = al.iterator();

        while(it.hasNext())

        {

            int x = (Integer)it.next();

            if(x%2!=0)

            {

                it.remove();

            }

        }

        System.out.println(al);

    }

}

• A.[10, 20]

• B.[15, 25]

• C.Compile Time Error

• D.RunTime Error

2. What is the output of this program?

import java.util.ArrayList;

public class ArrayListExample

{

     public static void main(String a[])

    {

        ArrayList al = new ArrayList();

        al.add("Sonu");

        al.add("Ram");

        al.add("Hello");

        al.add("Sonu");

        al.add("Hello");

        al.add("Hello");

        al.add("Hello");

        System.out.println(al.indexOf("Hello"));

    }

}

• A.6

• B.2

• C.5

• D.4

3. What is the output of this program?

import java.util.ArrayList;

public class ArrayListExample

{

     public static void main(String a[])

    {

        ArrayList al = new ArrayList();

        al.add("Sonu");

        al.add("Ram");

        al.add("Hello");

        al.add("Sonu");

        al.add("Hello");

        al.add("Hello");

        al.add("Hello");

        System.out.println(al.lastIndexOf("Hello"));

    }

}

• A.6

• B.2

• C.5

• D.4

4. What is the output of this program?

import java.util.*;

public class ArrayListExample

{

      public static void main(String a[])

    {

        ArrayList al = new ArrayList();

        ArrayList a2 = new ArrayList();

        al.add("Sonu");

        a2.add(1);

        al.add("Ram");

        a2.add(2);

        al.add("Hello");

        a2.add(3);

        al.addAll(2, a2);

        System.out.println(al);

    }

}

• A.[Sonu, Ram, Hello, 1, 2, 3,]

• B.[Sonu, Ram, 1, 2, 3, Hello]

• C.[Sonu, 1, Ram, 2, 3, Hello]

• D.[Sonu, Ram, 1, 2, 3]

5. What is the output of this program?

import java.util.*;

public class ArrayListExample

{

     public static void main(String a[])

     {

        ArrayList al = new ArrayList();

        al.add("Sonu");

        al.add("Ram");

        al.add("Hello");

        System.out.println(al.size());

    }

}

• A.10

• B.2

• C.3

• D.Compile Time Error

6. What is the output of this program?

import java.util.*;

public class ArrayListExample

{

     public static void main(String a[])

    {

        ArrayList al = new ArrayList();

        ArrayList a2 = new ArrayList();

        al.add("Sonu");

        a2.add(1);

        al.add("Ram");

        a2.add(2);

        al.add("Hello");

        a2.add(3);

        al.retainAll(a2);

        System.out.println(al);

    }

}

• A.[Sonu, Ram, Hello]

• B.[1, 2, 3]

• C.[]

• D.Compile Time Error

7. What is the output of this program?

import java.util.*;

public class ArrayListExample

{

     public static void main(String a[])

    {

        ArrayList al = new ArrayList();

        ArrayList a2 = new ArrayList();

        al.add("Sonu");

        a2.add(1);

        al.add("Ram");

        a2.add(2);

        al.add("Hello");

        a2.add(3);

        al.clear();

        System.out.println(a2);

    }

}

• A.[1, 2, 3]

• B.[]

• C.Compile Time Error

• D.RunTime Error

8. What is the output of this program?

import java.util.*;

public class ArrayListExample

{

     public static void main(String a[])

    {

        ArrayList al = new ArrayList();

        ArrayList a2 = new ArrayList();

        al.add("Sonu");

        a2.add(1);

        al.add("Ram");

        a2.add(2);

        al.add("Hello");

        a2.add(3);

        a2.set(1, "GLAU");

        System.out.println(a2);

    }

}

• A.[1, 2, 3]

• B.[1, GLAU, 3]

• C.[Sonu, GLAU, Hello]

• D.Compile Time Error

9. What is the output of this program?

import java.util.ArrayList;

public class ArrayListExample

{

    public static void main(String a[])

    {

        ArrayList  al = new ArrayList();

        al.add(10);

        al.add(15);

        al.add(20);

        al.add(25);

        Iterator it = al.iterator();

        while(it.hasNext())

        {

            int x = it.next();

            if(x%2!=0)

            {

                it.remove();

            }

        }

        System.out.println(al);

    }

}

• A.[10, 20]

• B.[15, 25]

• C.Compile Time Error

• D.RunTime Error

10. What is the output of this program?

import java.util.ArrayList;

class ArrayListExample

{

     public static void main(String a[])

    {

        ArrayList al = new ArrayList();

        al.add(1);

        al.add(2);

        al.add(3);

        al.remove(1);

        System.out.println(al);

    }

}

• A.[1, 3]

• B.[2, 3]

• C.Compile Time Error

• D.RunTime Error