Milestone 1 Quiz WTN

Which statement is not true about maps?

• All keys in a map are unique

• The return type of the values() method is a Collection

• The Map interface extends the Collection interface

• Elements of a LinkedHashMap are ordered by insertion order

What will be the output of the following program:

public class Demo{

public static void main(String args[]){

int variable1 = 10;

do{

if(variable1==10){

break;

}else{

variable1++;

System.out.println(variable1);

}

}while(variable1<10);

}

}

• a. 10

• b. 11

• c. No Output

• d. Compilation Error

import java.util.*;

public class TestCollection {

    public static void main(String args[]) {

        Object al = new ArrayList();

        Object hs = new HashSet();

        Object hm = new HashMap();

        System.out.println(String.format("%s,%s,%s", al instanceof Collection, hs instanceof Collection, hm instanceof Collection));

    }

}What is the result of attempting to compile and run the program?

• false,false,true

• true,true,false

• true,false,true

• true,true,true

What will be the output of the following program:

public class Demo{

public static void main(String args[]){

int[] myArray = {1,2,3,4,5};

for(int counter:myArray){

System.out.println(++counter);

}

}

}

• 2

  3

  4

  5

  6

• 1

  2

  3

  4

  5

• No Output

• Compilation Error

Given classes A, B, and C, where B extends A, and C extends B, and where all classes implement the instance method void doIt(). How can the doIt() method in A be called from an instance method in C?

• super.doIt()

• super.super.doIt()

• A.this.doIt()

• It is not possible

Using which one of the following keyword we can exclude some object properties from serialization process?

• transient

• exclude

• omit

• native

Which statement is true?

• Private methods of a superclass cannot be overridden n subclasses

• A subclass can override any method present in a superclass

• An overriding method can declare that it throws more exceptions than the method it is overriding

• The parameter list of an overriding  method must be a subset of the parameter list of the method that it is overriding

import java.util.*;

public class TestSortedMap {

    public static void main(String[] args) {

        Object o = new LinkedHashMap();

        System.out.println((o instanceof Map) + ",");

        System.out.println(o instanceof SortedMap);

    }

}What is the result of attempting to compile and run the program?

• false,false

• false,true

• true,false

• true,true

“Contains no duplicate elements.

“Can contain at most one null value.

“Elements are not key/value pairs.

“Accessing an element can be almost as fast as performing a similar operation on an array

Which of these classes provides the specified features?

• LinkedList

• TreeMap

• HashSet

• LinkedHashMap

Following is a file format which enables to handle multiple files into a single file

• JPG

• PNG

• TIF

• JAR