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Java MCQs

Q: What is the difference between JDK, JRE and JVM?

The JVM, or Java Virtual Machine, runs Java bytecode. The JRE, or Java Runtime Environment, contains the JVM plus the libraries needed to run Java programs. The JDK, or Java Development Kit, includes the JRE along with development tools such as the compiler javac, so it is needed to write and compile programs.

Q: Which operator is used to allocate memory to an array in Java?

The new operator is used to allocate memory to an array in Java, for example int[] marks = new int[10];. It creates the array object on the heap and initialises numeric elements to zero. The same operator is used to create objects from classes.

Java MCQs test your knowledge of the Java programming language, including the JVM, data types, operators, control statements, arrays and object-oriented ideas. They help computer science students and IT job applicants, and every question shows its correct answer instantly so you can check concepts as you practise.

Question 01 Java

Which OOP concept bundles data and methods in a class while hiding internal details through private fields?

Correct answer C. Encapsulation

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Question 02 Java

What is the size of the char data type in Java?

Correct answer B. 16 bits

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Question 03 Java

Which Java keyword, applied to a method, prevents subclasses from overriding it?

Correct answer C. final

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Question 04 Java

Which keyword does a Java class use to adopt an interface?

Correct answer B. implements

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Question 05 Java

Which keyword does a Java class use to inherit from another class?

Correct answer D. extends

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Question 06 Java

What is the default value of a boolean instance variable in Java?

Correct answer A. false

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Question 07 Java

What is the size of the int data type in Java?

Correct answer D. 32 bits

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Question 08 Java

What is the output of the Java statement System.out.println(“5” + 3 + 2);?

Correct answer C. 532

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Question 09 Java

What is the output of the Java statement System.out.println(10 / 4);?

Correct answer D. 2

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Question 10 Java

What is the output of the Java statement System.out.println(3 + 2 + “5”);?

Correct answer A. 55

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Question 11 Java

Which of the following are not Java modifiers?

Correct answer C. friendly

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Question 12 Java

In Java code, the line that begins with /* and ends with */ is known as?

Correct answer A. Multiline comment

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Question 13 Java

What is the full form of JVM?

Correct answer D. Java Virtual Machine

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Question 14 Java

Division operator has ____ precedence over multiplication operator

Correct answer C. Equal

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Question 15 Java

Which of the following are not the methods of the Thread class?

Correct answer C. go()

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Question 16 Java

What feature of OOP has a super-class sub-class concept?

Correct answer A. Hierarchical inheritance

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Question 17 Java

Modulus operator (%) can be applied to which of these?

Correct answer C. Both A and B

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Question 18 Java

Which statement transfer execution to different parts of your code based on the value of an expression?

Correct answer B. Switch

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Question 19 Java

Which of these is returned by Greater Than, Less Than and Equal To (i.e Relational) operator?

Correct answer C. Boolean

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Question 20 Java

Which of these is not a bitwise operator?

Correct answer D. <=' Operator

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About Java MCQs

This topic covers core Java that interviewers and written tests often check. Questions ask which component provides the runtime environment for bytecode, which is the Java Virtual Machine, and which operator allocates memory to arrays, the new operator. You will also meet instance variables created with each object, jump statements such as break, continue and return, and exception handling with try, catch and finally. Operator precedence items, including how division and multiplication share equal precedence, also appear. These basics are useful for software house tests, computer lecturer posts and placement rounds.

Exams that include Java MCQs

Pakistan

NTS
PPSC
FPSC
Lecturer tests

India

Campus placements
UGC NET
SSC CGL

Bangladesh

Government job tests
Bank job exams
BCS

Frequently asked questions

What is the difference between JDK, JRE and JVM?

The JVM, or Java Virtual Machine, runs Java bytecode. The JRE, or Java Runtime Environment, contains the JVM plus the libraries needed to run Java programs. The JDK, or Java Development Kit, includes the JRE along with development tools such as the compiler javac, so it is needed to write and compile programs.

Which operator is used to allocate memory to an array in Java?

The new operator is used to allocate memory to an array in Java, for example int[] marks = new int[10];. It creates the array object on the heap and initialises numeric elements to zero. The same operator is used to create objects from classes.

Last reviewed October 2026