Explore topic-wise MCQs in Testing Subject.

This section includes 657 Mcqs, each offering curated multiple-choice questions to sharpen your Testing Subject knowledge and support exam preparation. Choose a topic below to get started.

1.

What is the output of this program? import java.util.*; public class genericstack { Stack stk = new Stack (); public void push(E obj) { stk.push(obj); } public E pop() { E obj = stk.pop(); return obj; } } class Output { public static void main(String args[]) { genericstack gs = new genericstack(); gs.push(36); System.out.println(gs.pop()); } }

A. 0
B. 36
C. Runtime Error
D. Compilation Error
Answer» C. Runtime Error
Discussion
2.

What is the output of this program? public class BoxDemo { public static void addBox(U u, java.util.List> boxes) { Box box = new Box<>(); box.set(u); boxes.add(box); } public static void outputBoxes(java.util.List> boxes) { int counter = 0; for (Box box: boxes) { U boxContents = box.get(); System.out.println("Box #" + counter + " contains [" + boxContents.toString() + "]"); counter++; } } public static void main(String[] args) { java.util.ArrayList> listOfIntegerBoxes = new java.util.ArrayList<>(); BoxDemo.addBox(Integer.valueOf(10), listOfIntegerBoxes); BoxDemo.outputBoxes(listOfIntegerBoxes); } }

A. 10
B. Box #0 [10].
C. Box contains [10].
D. Box #0 contains [10].
Answer» E.
Discussion
3.

What is the output of this program? import java.util.*; public class genericstack { Stack stk = new Stack (); public void push(E obj) { stk.push(obj); } public E pop() { E obj = stk.pop(); return obj; } } class Output { public static void main(String args[]) { genericstack gs = new genericstack(); gs.push("Hello"); System.out.print(gs.pop() + " "); genericstack gs = new genericstack(); gs.push(36); System.out.println(gs.pop()); } }

A. Error
B. Hello
C. 36
D. Hello 36
Answer» E.
Discussion
4.

Which of the following is good coding practice to determine oddity? i) public boolen abc(int num) { return num % 2 == 1; } ii) public boolean xyz(int num) { return (num & 1)!= 0; }

A. I
B. Ii
C. Option (i) causes compilation error
D. Option (ii) causes compilation error
Answer» C. Option (i) causes compilation error
Discussion
5.

What one of the following is best practice to handle Null Pointer exception? i) int noOfStudents = line.listStudents().count; ii) int noOfStudents = getCountOfStudents(line); public int getCountOfStudents(List line) { if(line != null) { if(line.listOfStudents() != null) { return line.listOfStudents().size(); } } throw new NullPointerException("List is empty"); }

A. Option (i)
B. Option (ii)
C. Compilation Error
D. Option (ii) gives incorrect result
Answer» C. Compilation Error
Discussion
6.

What is the output of this program? class evaluate { public static void main(String args[]) { int a[] = {1,2,3,4,5}; int d[] = a; int sum = 0; for (int j = 0; j < 3; ++j) sum += (a[j] * d[j + 1]) + (a[j + 1] * d[j]); System.out.println(sum); } }

A. 38
B. 39
C. 40
D. 41
Answer» D. 41
Discussion
7.

What is the output of this program? class array_output { public static void main(String args[]) { int array_variable [] = new int[10]; for (int i = 0; i < 10; ++i) { array_variable[i] = i/2; array_variable[i]++; System.out.print(array_variable[i] + " "); i++; } } }

A. 0 2 4 6 8
B. 1 2 3 4 5
C. 0 1 2 3 4 5 6 7 8 9
D. 1 2 3 4 5 6 7 8 9 10
Answer» C. 0 1 2 3 4 5 6 7 8 9
Discussion
8.

What is the prototype of the default constructor of this class? public class prototype { }

A. Prototype( )
B. Prototype(void)
C. Public prototype(void)
D. Public prototype( )
Answer» E.
Discussion
9.

What is the error in this code? byte b = 50; b = b * 50;

A. B cannot contain value 100, limited by its range
B. * operator has converted b * 50 into int, which can not be converted to byte without casting
C. B cannot contain value 50
D. No error in this code
Answer» C. B cannot contain value 50
Discussion
10.

What is the output of this program? class char_increment { public static void main(String args[]) { char c1 = 'D'; char c2 = 84; c2++; c1++; System.out.println(c1 + " " + c2); } }

A. E U
B. U E
C. V E
D. U F
Answer» B. U E
Discussion
11.

What is the output of this program? class conversion { public static void main(String args[]) { double a = 295.04; int b = 300; byte c = (byte) a; byte d = (byte) b; System.out.println(c + " " + d); } }

A. 38 43
B. 39 44
C. 295 300
D. 295.04 300
Answer» C. 295 300
Discussion
12.

Which of these class is used to encapsulate IP address and DNS?

A. DatagramPacket
B. URL
C. InetAddress
D. ContentHandler
Answer» D. ContentHandler
Discussion
13.

What is the output of this program? import java.net.*; class networking { public static void main(String[] args) throws UnknownHostException { InetAddress obj1 = InetAddress.getByName("mcqsmentor.com"); InetAddress obj2 = InetAddress.getByName("mcqsmentor.com"); boolean x = obj1.equals(obj2); System.out.print(x); } }

A. 0
B. 1
C. True
D. False
Answer» D. False
Discussion
14.

What is the output of this program? import java.net.*; class networking { public static void main(String[] args) throws UnknownHostException { InetAddress obj1 = InetAddress.getByName("cisco.com"); InetAddress obj2 = InetAddress.getByName("mcqsmentor.com"); boolean x = obj1.equals(obj2); System.out.print(x); } }

A. 0
B. 1
C. True
D. False
Answer» D. False
Discussion
15.

What is the output of this program? import java.net.*; class networking { public static void main(String[] args) throws MalformedURLException { URL obj = new URL("https://www.mcqsmentor.com/"); System.out.print(obj.toExternalForm()); } }

A. mcqsmentor
B. mcqsmentor.com
C. www.mcqsmentor.com
D. https://www.mcqsmentor.com/
Answer» E.
Discussion
16.

What is the output of this program? import java.io.*; class streams { public static void main(String[] args) { try { FileOutputStream fos = new FileOutputStream("serial"); ObjectOutputStream oos = new ObjectOutputStream(fos); oos.writeInt(5); oos.flush(); oos.close(); } catch(Exception e) { System.out.println("Serialization" + e); System.exit(0); } try { int z; FileInputStream fis = new FileInputStream("serial"); ObjectInputStream ois = new ObjectInputStream(fis); z = ois.readInt(); ois.close(); System.out.println(x); } catch (Exception e) { System.out.print("deserialization"); System.exit(0); } } }

A. 5
B. Void
C. Serialization
D. Deserialization
Answer» B. Void
Discussion
17.

What is the output of this program? import java.io.*; class serialization { public static void main(String[] args) { try { Myclass object1 = new Myclass("Hello", -7, 2.1e10); FileOutputStream fos = new FileOutputStream("serial"); ObjectOutputStream oos = new ObjectOutputStream(fos); oos.writeObject(object1); oos.flush(); oos.close(); } catch(Exception e) { System.out.println("Serialization" + e); System.exit(0); } try { int x; FileInputStream fis = new FileInputStream("serial"); ObjectInputStream ois = new ObjectInputStream(fis); x = ois.readInt(); ois.close(); System.out.println(x); } catch (Exception e) { System.out.print("deserialization"); System.exit(0); } } } class Myclass implements Serializable { String s; int i; double d; Myclass(String s, int i, double d) { this.d = d; this.i = i; this.s = s; } }

A. -7
B. Hello
C. 2.1E10
D. Deserialization
Answer» E.
Discussion
18.

What is the output of this program? import java.io.*; class Chararrayinput { public static void main(String[] args) { String obj = "abcdef"; int length = obj.length(); char c[] = new char[length]; obj.getChars(0,length,c,0); CharArrayReader input1 = new CharArrayReader(c); CharArrayReader input2 = new CharArrayReader(c, 0, 3); int i; try { while ((i = input1.read()) != -1) { System.out.print((char)i); } } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } }

A. Abc
B. Abcd
C. Abcde
D. Abcdef
Answer» E.
Discussion
19.

What is the output of this program? import java.io.*; class Chararrayinput { public static void main(String[] args) { String obj = "abcdef"; int length = obj.length(); char c[] = new char[length]; obj.getChars(0, length, c, 0); CharArrayReader input1 = new CharArrayReader(c); CharArrayReader input2 = new CharArrayReader(c, 0, 3); int i; try { while ((i = input2.read()) != -1) { System.out.print((char)i); } } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } }

A. Abc
B. Abcd
C. Abcde
D. Abcdef
Answer» B. Abcd
Discussion
20.

What is the output of this program? import java.io.*; class Chararrayinput { public static void main(String[] args) { String obj = "abcdefgh"; int length = obj.length(); char c[] = new char[length]; obj.getChars(0, length, c, 0); CharArrayReader input1 = new CharArrayReader(c); CharArrayReader input2 = new CharArrayReader(c, 1, 4); int i; int j; try { while ((i = input1.read()) == (j = input2.read())) { System.out.print((char)i); } } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } }

A. Abc
B. Abcd
C. Abcde
D. None of the mentioned
Answer» E.
Discussion
21.

Which of these methods of Character wrapper can be used to obtain the char value contained in Character object.

A. Get()
B. GetVhar()
C. CharValue()
D. GetCharacter()
Answer» D. GetCharacter()
Discussion
22.

What is the output of this program? class Output { public static void main(String args[]) { int a = Character.MAX_VALUE; System.out.print((char)a); } }

A. <
B. >
C. ?
D. $
Answer» D. $
Discussion
23.

What is the output of this program? class Output { public static void main(String args[]) { int a = Character.MIN_VALUE; System.out.print((char)a); } }

A. <
B. !
C.
D. @Space
Answer» E.
Discussion
24.

What is the output of this program? class Output { public static void main(String args[]) { String str = "true"; boolean x = Boolean.valueOf(str); System.out.print(x); } }

A. True
B. False
C. Compilation Error
D. Runtime Error
Answer» B. False
Discussion
25.

What is the output of this program? class Output { public static void main(String args[]) { String str = "true false true"; boolean x = Boolean.valueOf(str); System.out.print(x); } }

A. True
B. False
C. Compilation Error
D. Runtime Error
Answer» C. Compilation Error
Discussion
26.

What is the output of this program? class exception_handling { public static void main(String args[]) { try { int a[] = {1, 2,3 , 4, 5}; for (int i = 0; i < 7; ++i) System.out.print(a[i]); } catch(ArrayIndexOutOfBoundsException e) { System.out.print("0"); } } }

A. 12345
B. 12345A
C. 12345B
D. Compilation Error
Answer» D. Compilation Error
Discussion
27.

What is the output of this program? class A { int x; int y; void display() { System.out.print(x + " " + y); } } class Output { public static void main(String args[]) { A obj1 = new A(); A obj2 = new A(); obj1.x = 1; obj1.y = 2; obj2 = obj1.clone(); obj1.display(); obj2.display(); } }

A. 1 2 0 0
B. 1 2 1 2
C. 0 0 0 0
D. System Dependent
Answer» C. 0 0 0 0
Discussion
28.

What is the output of this program? class Output { public static void main(String args[]) { double x = 3.14; int y = (int) Math.abs(x); System.out.print(y); } }

A. 0
B. 3
C. 3.0
D. 3.1
Answer» C. 3.0
Discussion
29.

What is the output of this program? class Output { public static void main(String args[]) { Double i = new Double(257.5); Double x = i.MAX_VALUE; System.out.print(x); } }

A. 0
B. 1.7976931348623157E308
C. 1.7976931348623157E30
D. None of the mentioned
Answer» C. 1.7976931348623157E30
Discussion
30.

What is the output of this program? class Output { public static void main(String args[]) { Double i = new Double(257.5); Double x = i.MIN_VALUE; System.out.print(x); } }

A. 0
B. 4.9E-324
C. 1.7976931348623157E308
D. None of the mentioned
Answer» C. 1.7976931348623157E308
Discussion
31.

What is the output of this program? class Output { public static void main(String args[]) { Double i = new Double(257.578123456789); float x = i.floatValue(); System.out.print(x); } }

A. 0
B. 257.0
C. 257.57812
D. 257.578123456789
Answer» D. 257.578123456789
Discussion
32.

What is the output of this program? class Output { public static void main(String args[]) { double x = 3.14; int y = (int) Math.floor(x); System.out.print(y); } }

A. 0
B. 3
C. 3.0
D. 4
Answer» C. 3.0
Discussion
33.

What is the output of this program? class Output { public static void main(String args[]) { char a[] = {'a', '5', 'A', ' '}; System.out.print(Character.isDigit(a[0])+ " "); System.out.print(Character.isWhitespace(a[3])+ " "); System.out.print(Character.isUpperCase(a[2])); } }

A. True false true
B. False true true
C. True true false
D. False false false
Answer» C. True true false
Discussion
34.

What is the output of this program? class Output { public static void main(String args[]) { char a = (char) 98; a = Character.toUpperCase(a); System.out.print(a); } }

A. b
B. c
C. B
D. C
Answer» D. C
Discussion
35.

What is the output of this program? class Output { public static void main(String args[]) { char a = '@'; boolean x = Character.isLetter(a); System.out.print(x); } }

A. True
B. False
C.
D. @B
Answer» C.
Discussion
36.

What is the output of this program? class Output { public static void main(String args[]) { String str = "true false"; boolean x = Boolean.parseBoolean(str); System.out.print(x); } }

A. True
B. False
C. System Dependent
D. Compilation Error
Answer» C. System Dependent
Discussion
37.

What is the output of this program? class Output { public static void main(String args[]) { String x = Boolean.toString(false); } }

A. True
B. False
C. System Dependent
D. Compilation Error
Answer» C. System Dependent
Discussion
38.

What is the output of this program? class Output { public static void main(String args[]) { double x = 102; double y = 5; double z = Math.IEEEremainder(x, y); System.out.print(z);} } }

A. 0
B. 1
C. 2
D. 3
Answer» D. 3
Discussion
39.

Will this program generate same output is executed again? class Output { public static void main(String args[]) { int y = double z = Math.random(); System.out.print(y); } }

A. Yes
B. No
C. Compiler Dependent
D. Operating System Dependent
Answer» C. Compiler Dependent
Discussion
40.

What is the value of d after this line of code has been executed? double d = Math.round ( 2.5 + Math.random() );

A. 2
B. 3
C. 4
D. 2.5
Answer» C. 4
Discussion
41.

What is the output of this program? class newthread implements Runnable { Thread t; newthread() { t = new Thread(this,"My Thread"); t.start(); } } class multithreaded_programing { public static void main(String args[]) { new newthread(); } }

A. My Thread
B. Thread[My Thread,5,main].
C. Compilation Error
D. Runtime Error
Answer» D. Runtime Error
Discussion
42.

What is the output of this program? class newthread implements Runnable { Thread t; newthread() { t = new Thread(this,"My Thread"); t.start(); } public void run() { System.out.println(t); } } class multithreaded_programing { public static void main(String args[]) { new newthread(); } }

A. My Thread
B. Thread[My Thread,5,main].
C. Compilation Error
D. Runtime Error
Answer» B. Thread[My Thread,5,main].
Discussion
43.

Which of the following are valid calls to Math.max? 1. Math.max(1,4) 2. Math.max(2.3, 5) 3. Math.max(1, 3, 5, 7) 4. Math.max(-1.5, -2.8f)

A. 1, 2 and 4
B. 2, 3 and 4
C. 1, 2 and 3
D. 3 and 4
Answer» B. 2, 3 and 4
Discussion
44.

Select how you would start the program to cause it to print: Arg is 2 public class Myfile { public static void main (String[] args) { String biz = args[1]; String baz = args[2]; String rip = args[3]; System.out.println("Arg is " + rip); } }

A. Java Myfile 222
B. Java Myfile 1 2 2 3 4
C. Java Myfile 1 3 2 2
D. Java Myfile 0 1 2 3
Answer» D. Java Myfile 0 1 2 3
Discussion
45.

What is the output of this program? class Output { public static void main(String args[]) { Integer i = new Integer(257); float x = i.floatValue(); System.out.print(x); } }

A. 0
B. 1
C. 257
D. 257.0
Answer» E.
Discussion
46.

What is the output of this program? class Output { public static void main(String args[]) { Long i = new Long(256); System.out.print(i.hashCode()); } }

A. 256
B. 256.0
C. 256.00
D. 257.00
Answer» B. 256.0
Discussion
47.

What is the output of this program? class Output { public static void main(String args[]) { byte a[] = { 65, 66, 67, 68, 69, 70 }; byte b[] = { 71, 72, 73, 74, 75, 76 }; System.arraycopy(a, 2, b, 1, a.length-2); System.out.print(new String(a) + " " + new String(b)); } }

A. ABCDEF GHIJKL
B. ABCDEF GCDEFL
C. GHIJKL ABCDEF
D. GCDEFL GHIJKL
Answer» C. GHIJKL ABCDEF
Discussion
48.

What is the output of this program? class Output { public static void main(String args[]) { byte a[] = { 65, 66, 67, 68, 69, 70 }; byte b[] = { 71, 72, 73, 74, 75, 76 }; System.arraycopy(a, 1, b, 3, 0); System.out.print(new String(a) + " " + new String(b)); } }

A. ABCDEF GHIJKL
B. ABCDEF GCDEFL
C. GHIJKL ABCDEF
D. GCDEFL GHIJKL
Answer» B. ABCDEF GCDEFL
Discussion
49.

What is the output of this program? import java.lang.System; class Output { public static void main(String args[]) { byte a[] = { 65, 66, 67, 68, 69, 70 }; byte b[] = { 71, 72, 73, 74, 75, 76 }; System.arraycopy(a, 0, b, 3, a.length - 3); System.out.print(new String(a) + " " + new String(b)); } }

A. ABCDEF ABCDEF
B. ABCDEF GHIJKL
C. ABCDEF GHIABC
D. GHIJKL GHIJKL
Answer» D. GHIJKL GHIJKL
Discussion
50.

What is the output of this program? import java.lang.System; class Output { public static void main(String args[]) { byte a[] = { 65, 66, 67, 68, 69, 70 }; byte b[] = { 71, 72, 73, 74, 75, 76 }; System.arraycopy(a, 2, b, 3, a.length - 4); System.out.print(new String(a) + " " + new String(b)); } }

A. ABCDEF ABCDEF
B. ABCDEF GHIJKL
C. ABCDEF GHIABC
D. ABCDEF GHICDL
Answer» E.
Discussion