Explore topic-wise MCQs in Java Programming.

This section includes 40 Mcqs, each offering curated multiple-choice questions to sharpen your Java Programming knowledge and support exam preparation. Choose a topic below to get started.

1.

What is the output of below snippet?import java.util.*;public class Map_Example{ public static void main(String[] args) { Map mapSample = new TreeMap(); mapSample.put(4, null); mapSample.put(0, null); mapSample.put(3, null); mapSample.put(2, null); mapSample.put(1, null); System.out.println(mapSample); }}

A. {0=null, 1=null, 2=null, 3=null, 4=null}
B. Runtime Error
C. Compilation Error
D. {3=null, 0=null, 2=null, 1=null, 4=null}
E. None of these
Answer» B. Runtime Error
Discussion
2.

What is the output of this program?import java.util.*; public class TreeSet_Example { public static void main(String args[]) { TreeSet object = new TreeSet(); object.add("7"); object.add("0"); object.add("9"); object.add("5"); object.add("6"); System.out.println(object); } }

A. Runtime Error
B. Compilation Error
C. [0, 5, 6, 7, 9]
D. [6, 7, 9]
E. [0, 5, 6, 7]
Answer» D. [6, 7, 9]
Discussion
3.

What is the output of this program?import java.util.*; public class vector_Example { public static void main(String args[]) { Vector object = new Vector(6,3); object.addElement(new Integer(5)); object.addElement(new Integer(7)); object.addElement(new Integer(9)); System.out.println(object.elementAt(2)); } }

A. 6, 3
B. 5
C. 7
D. 9
E. None of these
Answer» E. None of these
Discussion
4.

What is the output of this program?import java.util.*; public class Map_Exmple { public static void main(String args[]) { TreeMap object = new TreeMap(); object.put("I", new Integer(9)); object.put("L", new Integer(12)); object.put("U", new Integer(21)); System.out.println(object.entrySet()); } }

A. 9, 12, 21
B. I, L, U
C. [9, 12, 21]
D. [I=9, L=12, U=21]
E. None of these
Answer» E. None of these
Discussion
5.

What is the output of this program?import java.util.*; public class Map_Example { public static void main(String args[]) { HashMap object = new HashMap(); object.put("I", new Integer(9)); object.put("L", new Integer(12)); object.put("U", new Integer(21)); System.out.println(object.get("L")); } }

A. 9
B. 12
C. 21
D. [I, L, U]
E. None of these
Answer» C. 21
Discussion
6.

What is the output of this program?import java.util.*; public class Map_Example { public static void main(String args[]) { HashMap object = new HashMap(); object.put("D", new Integer(4)); object.put("E", new Integer(5)); object.put("F", new Integer(6)); System.out.println(object.keySet()); } }

A. {D=4, E=5, F=6}
B. [D, E, F]
C. [D, E, F] 3
D. [D=4, E=5, F=6]
E. None of these
Answer» C. [D, E, F] 3
Discussion
7.

What is the output of this program?import java.util.*; public class Map_Example { public static void main(String args[]) { HashMap object = new HashMap(); object.put("D", new Integer(4)); object.put("E", new Integer(5)); object.put("F", new Integer(6)); System.out.println(object); } }

A. {D=4, E=5, F=6}
B. {D, E, F}
C. {E=5, F=6}
D. Runtime Error
E. Compilation Error
Answer» B. {D, E, F}
Discussion
8.

What is the output of this program?import java.util.*; public class hashtable_Example { public static void main(String args[]) { Hashtable object = new Hashtable(); object.put("I", new Integer(10)); object.put("L", new Integer(60)); object.put("U", new Integer(25)); System.out.print(object.contains(new Integer(25))); } }

A. True
B. U
C. L
D. False
E. None of these
Answer» B. U
Discussion
9.

What is the output of this program?import java.util.*; public class properties_Example { public static void main(String args[]) { Properties object = new Properties(); object.put("PQ", new Integer(23)); object.put("SR", new Integer(46)); object.put("UV", new Integer(25)); System.out.print(object.keySet()); } }

A. [PQ, UV, SR]
B. [PQ, UV]
C. [UV, SR]
D. [23, 46, 25]
E. None of these
Answer» B. [PQ, UV]
Discussion
10.

What is the output of this program?import java.util.*; public class hashtable_Example { public static void main(String args[]) { Hashtable object = new Hashtable(); object.put("P", new Integer(12)); object.put("Q", new Integer(21)); object.put("R", new Integer(18)); System.out.print(object.toString()); } }

A. {R=18, Q=21}
B. {Q=21, P=12}
C. {R=18, P=12}
D. {R=18, Q=21, P=12}
E. {P=12, R=18}
Answer» E. {P=12, R=18}
Discussion
11.

What is the output of this program?import java.util.*; public class hashtable { public static void main(String args[]) { Hashtable object = new Hashtable(); object.put("D", new Integer(30)); object.put("E", new Integer(70)); object.put("F", new Integer(60)); object.remove(new String("E")); System.out.print(object); } }

A. {F=60, D=30, E=70}
B. {D=30, E=70}
C. {F=60, D=30}
D. {D=30, E=70, F=60}
E. None of these
Answer» D. {D=30, E=70, F=60}
Discussion
12.

What is the output of this program?import java.util.*; public class hashtable { public static void main(String args[]) { Hashtable object = new Hashtable(); object.put("I", new Integer(25)); object.put("L", new Integer(60)); object.put("U", new Integer(20)); object.clear(); System.out.print(object.size()); } }

A. 4
B. 3
C. 2
D. 1
Answer» F.
Discussion
13.

What is the output of this program?import java.util.*; public class Bitset_Example { public static void main(String args[]) { BitSet object = new BitSet(10); for (int k = 0; k < 6; ++k) object.set(k); object.clear(2); System.out.print(object); } }

A. {0, 1, 3, 4, 5}
B. {0, 1, 3, 4}
C. {1, 3, 4, 5}
D. {0, 1, 3, 4, 5, 6}
E. None of these
Answer» B. {0, 1, 3, 4}
Discussion
14.

What is the output of this program? import java.util.*; public class Bitset_Example { public static void main(String args[]) { BitSet object0 = new BitSet(12); BitSet object1 = new BitSet(15); for (int k = 0; k < 7; ++k) { object0.set(k); } for (int k = 3; k < 15; ++k) { object1.set(k); } object0.and(object1); System.out.print(object0); } }

A. {3, 4, 5}
B. {4, 5, 6}
C. {4, 5}
D. {3, 4, 5, 6}
E. None of these
Answer» E. None of these
Discussion
15.

What is the output of this program?import java.util.*; public class date_Example { public static void main(String args[]) { Date object = new Date(); System.out.print(object); } }

A. Any Garbage Value
B. Prints Present Time & Date
C. Runtime Error
D. Prints Present Date
E. None of these
Answer» C. Runtime Error
Discussion
16.

What is the output of this program?import java.util.*; public class Bitset_Exmple { public static void main(String args[]) { BitSet object = new BitSet(10); for (int k = 0; k < 6; ++k) object.set(k); System.out.print(object.get(6)); } }

A. 6
B. 10
C. True
D. False
E. None of these
Answer» E. None of these
Discussion
17.

What is the output of this program?import java.util.*; public class Bitset_Example { public static void main(String args[]) { BitSet object = new BitSet(10); for (int K = 0; K < 6; ++K) object.set(K); object.clear(2); System.out.print(object.length() + " " + object.size()); } }

A. 6 60
B. 60 6
C. 6 64
D. 64 6
E. None of these
Answer» D. 64 6
Discussion
18.

What is the output of this program?import java.util.*; public class Array_Examle { public static void main(String args[]) { int p[] = new int [10]; for (int k = 7; k > 0 ; k--) { p[7-k] = k; } Arrays.fill(p, 1, 4, 8); for (int k = 0; k < 5 ; k++) { System.out.print(p[k]); } } }

A. 56885
B. 678867
C. 328832
D. 78883
E. 68883
Answer» E. 68883
Discussion
19.

What is the output of this program?import java.util.*; public class Bitset_Example { public static void main(String args[]) { BitSet object = new BitSet(8); for (int k = 0; k < 6; ++k) object.set(k); object.clear(4); System.out.print(object); } }

A. {0, 1, 3, 5}
B. {0, 1, 2, 5}
C. {0, 1, 2, 3, 5}
D. {0, 1, 2, 3, 4, 5}
E. None of these
Answer» D. {0, 1, 2, 3, 4, 5}
Discussion
20.

What is the output of this program?import java.util.*; public class Collection_iterators_Example { public static void main(String args[]) { LinkedList listobject = new LinkedList(); listobject.add(new Integer(10)); listobject.add(new Integer(9)); listobject.add(new Integer(6)); listobject.add(new Integer(11)); Iterator Itr = listobject.iterator(); Collections.reverse(listobject); Collections.sort(listobject); while(Itr.hasNext()) System.out.print(Itr.next() + " "); } }

A. 10 9 6 11
B. 10 9 6
C. 6 9 10 11
D. 11 10 9 6
E. None of these
Answer» D. 11 10 9 6
Discussion
21.

What is the output of this program?import java.util.*; public class Collection_iterators_Example { public static void main(String args[]) { LinkedList listObject = new LinkedList(); listObject.add(new Integer(3)); listObject.add(new Integer(9)); listObject.add(new Integer(7)); listObject.add(new Integer(2)); Iterator itr = listObject.iterator(); Collections.reverse(listObject); while(itr.hasNext()) System.out.print(itr.next() + " "); } }

A. 2 7 9 3
B. 3 9 7 2
C. 2 3 7 9
D. 7 9 3 2
E. None of these
Answer» B. 3 9 7 2
Discussion
22.

What is the output of this program?import java.util.*; public class Collection_iterators_Example { public static void main(String args[]) { ListIterator object = List.istIterator(); if(object.previousIndex()!= -1) while(object.hasNext()) System.out.print(object.next() + " "); else System.out.print("EMPTY"); } }

A. Compilation Error
B. Runtime Error
C. EMPTY
D. empty
E. None of these
Answer» B. Runtime Error
Discussion
23.

What is the output of this program?import java.util.*; public class Collection_AlgosExample { public static void main(String args[]) { LinkedList listobject = new LinkedList(); listobject.add(new Integer(13)); listobject.add(new Integer(23)); listobject.add(new Integer(3)); listobject.add(new Integer(11)); Iterator Itr = listobject.iterator(); Collections.reverse(listobject); Collections.sort(listobject); while(Itr.hasNext()) System.out.print(Itr.next() + " "); } }

A. 3 11 13 23
B. 13 23 3 11
C. 3 11 13
D. 13 11 3
E. 23 13 11 3
Answer» B. 13 23 3 11
Discussion
24.

What is the output of this program? import java.util.*; public class Collection_AlgorithmsExample { public static void main(String args[]) { LinkedList listObject = new LinkedList(); listObject.add(new Integer(22)); listObject.add(new Integer(28)); listObject.add(new Integer(25)); listObject.add(new Integer(21)); Iterator Itr = listObject.iterator(); Collections.reverse(listObject); while(Itr.hasNext()) System.out.print(Itr.next() + " "); } }

A. 22 28 25 21
B. 21 25 28 22
C. 28 25 22 21
D. 21 22 25 28
E. None of these
Answer» C. 28 25 22 21
Discussion
25.

What is the output of this program?import java.util.*; public class Collection_iterator_Example { public static void main(String args[]) { LinkedList listobject = new LinkedList(); listobject.add(new Integer(10)); listobject.add(new Integer(3)); listobject.add(new Integer(15)); listobject.add(new Integer(12)); Iterator Itr = listobject.iterator(); Collections.reverse(listobject); Collections.shuffle(listobject); Itr.next(); Itr.remove(); while(Itr.hasNext()) System.out.print(Itr.next() + " "); } }

A. 12 10 15
B. 10 3 15 12
C. 3 15 12 10
D. 3 10 12 15
E. None of these
Answer» B. 10 3 15 12
Discussion
26.

What is the output of this program?import java.util.*; public class stack_Example { public static void main(String args[]) { Stack object = new Stack(); object.push(new Integer(20)); object.push(new Integer(12)); object.pop(); object.push(new Integer(60)); System.out.println(object); } }

A. [20, 60]
B. [20, 12, 60]
C. [20, 12]
D. [12, 60]
E. None of these
Answer» B. [20, 12, 60]
Discussion
27.

What is the output of this program?import java.util.*; public class vector_Example { public static void main(String args[]) { Vector object = new Vector(6,3); object.addElement(new Integer(10)); object.addElement(new Integer(20)); object.addElement(new Integer(50)); object.removeAll(object); System.out.println(object.isEmpty()); } }

A. True
B. False
C. 0
D. 1
E. None of these
Answer» B. False
Discussion
28.

What is the output of this program?import java.util.*; public class vector_Example { public static void main(String args[]) { Vector object = new Vector(6,3); object.addElement(new Integer(10)); object.addElement(new Integer(20)); object.addElement(new Integer(60)); object.insertElementAt(new Integer(80), 1); System.out.println(object); } }

A. [10, 20, 60, 80]
B. [10, 20, 60] 4
C. [10, 20, 60]
D. [20, 60, 80]
E. [10, 80, 20, 60]
Answer» F.
Discussion
29.

What is the output of this program?import java.util.*; public class vector { public static void main(String args[]) { Vector object = new Vector(6,3); object.addElement(new Integer(9)); object.addElement(new Integer(7)); object.addElement(new Integer(3)); System.out.println(object.capacity()); } }

A. 3
B. 6
C. 9
D. 7
E. None of these
Answer» C. 9
Discussion
30.

What is the output of this program?import java.util.*; public class HashSet_Example { public static void main(String args[]) { HashSet object = new HashSet(); object.add("I"); object.add("L"); object.add("U"); System.out.println(object + " " + object.size()); } }

A. [U, I, L]
B. [I, L, U] 3
C. [I, L, U]
D. [U, I, L] 3
E. None of these
Answer» E. None of these
Discussion
31.

What is the output of this program?import java.util.*; public class Linkedlist_Example { public static void main(String args[]) { LinkedList object = new LinkedList(); object.add("I"); object.add("L"); object.add("U"); object.removeFirst(); System.out.println(object); } }

A. [I, L, U]
B. [I, L]
C. [L, U]
D. [I, U]
E. None of these
Answer» D. [I, U]
Discussion
32.

What is the output of this program?import java.util.*; public class Linkedlist_Example { public static void main(String args[]) { LinkedList object = new LinkedList(); object.add("O"); object.add("V"); object.add("E"); object.addFirst("L"); System.out.println(object); } }

A. [L]
B. [L, O]
C. [L, O, V]
D. [L, O, V, E]
E. None of these
Answer» E. None of these
Discussion
33.

What is the output of this program?import java.util.*;public class Output { public static void main(String args[]) { ArrayList object = new ArrayList(); object.add("Y"); object.add("O"); object.add("U"); object.ensureCapacity(3); object.trimToSize(); System.out.println(object.size()); } }

A. 0
B. 1
C. 2
D. 3
E. None of these
Answer» E. None of these
Discussion
34.

What is the output of this program?import java.util.*; public class Result { public static void main(String args[]) { ArrayList object = new ArrayList(); object.add("Y"); object.add("O"); object.add("U"); object.ensureCapacity(5); System.out.println(object.size()); } }

A. 3
B. 2
C. 6
D. 0
E. Any Garbage Value
Answer» B. 2
Discussion
35.

What is the output of this program? import java.util.*; public class Result { public static void main(String args[]) { ArrayList object = new ArrayList(); object.add("Y"); object.add("O"); object.add("U"); System.out.println(object.size()); } }

A. Y
B. O
C. U
D. 3
E. None of these
Answer» E. None of these
Discussion
36.

What is the output of this program?import java.util.*; public class Arraylist_Example { public static void main(String args[]) { ArrayList object = new ArrayList(); object.add("L"); object.add("V"); object.add("E"); object.add(1, "O"); System.out.println(object); } }

A. [L, O]
B. [O]
C. [L, O, V, E]
D. [L, O, V]
E. None of these
Answer» D. [L, O, V]
Discussion
37.

What is the output of this program?import java.util.*; public class Collection_AlgorithmsExample { public static void main(String args[]) { LinkedList listObject = new LinkedList(); listObject.add(new Integer(2)); listObject.add(new Integer(8)); listObject.add(new Integer(5)); listObject.add(new Integer(1)); Iterator Itr = listObject.iterator(); while(Itr.hasNext()) System.out.print(Itr.next() + " "); } }

A. 25 28 52 31
B. 55 31 28 25
C. 31 55 28 25
D. 28 25 55 31
E. None of these
Answer» B. 55 31 28 25
Discussion
38.

Which of these is the interface of legacy is implemented by Hashtable and Dictionary classes?

A. Hashtable
B. HashMap
C. Enumeration
D. Map
E. None of these
Answer» E. None of these
Discussion
39.

Which of this interface is not a part of Java s collection framework?

A. SortedMap
B. List
C. SortedList
D. Set
E. None of these
Answer» D. Set
Discussion
40.

Which of these classes is not part of Java s collection framework?

A. Stack
B. Queue
C. Array
D. Maps
E. None of these
Answer» E. None of these
Discussion