Java MCQs

Question 1

Which of the following is NOT a Java primitive data type?

Accepted Answer

String

Answer

int

Answer

boolean

Answer

char

Question 2

Which keyword is used by a class to inherit from another class in Java?

Accepted Answer

extends

Answer

implements

Answer

inherits

Answer

super

Question 3

Which of the following is NOT a Java primitive data type?

Accepted Answer

String

Answer

boolean

Answer

char

Answer

int

Question 4

Which of the following keywords is used to inherit a class in Java?

Accepted Answer

extends

Answer

implements

Answer

inherits

Answer

super

Question 5

Which of the following is a checked exception in Java?

Accepted Answer

IOException

Answer

NullPointerException

Answer

ArithmeticException

Answer

IllegalArgumentException

Question 6

Which Java collection class does NOT guarantee the insertion order of elements?

Accepted Answer

HashSet

Answer

ArrayList

Answer

LinkedHashSet

Answer

LinkedList

Question 7

Why does Java NOT support multiple inheritance through classes?

Accepted Answer

To prevent ambiguity issues such as the Diamond Problem

Answer

Because classes cannot have more than one constructor

Answer

To reduce the bytecode file size of compiled classes

Answer

Because the JVM stack cannot hold multiple parent references

Question 8

What is the default value of a local boolean variable declared inside a method in Java?

Accepted Answer

No default value (Causes a compile error if accessed before initialization)

Answer

false

Answer

true

Answer

null

Question 9

What is the default value of a local boolean variable declared inside a method in Java?

Accepted Answer

No default value (Causes a compile error if accessed before initialization)

Answer

false

Answer

true

Answer

null

Question 10

Can a Java class directly inherit multiple classes using the extends keyword?

Accepted Answer

No, Java does not support multiple class inheritance

Answer

Yes, separated by commas

Answer

Yes, if all parent classes are abstract

Answer

Only in Java 17 and later

Question 11

Which of the following members of a superclass are NEVER inherited by a subclass?

Accepted Answer

Constructors

Answer

Public methods

Answer

Protected fields

Answer

Package-private methods in the same package

Question 12

Which component of the Java environment is responsible for converting bytecode into machine-specific native machine code at runtime?

Accepted Answer

JIT Compiler

Answer

JDK Compiler (javac)

Answer

ClassLoader

Answer

Garbage Collector

Question 13

Which component of the Java environment is responsible for converting bytecode into machine-specific native machine code at runtime?

Accepted Answer

JIT Compiler

Answer

javac

Answer

Class Loader

Answer

Garbage Collector

Question 14

Which memory area in the JVM stores newly created objects and instance variables?

Accepted Answer

Heap Memory

Answer

Stack Memory

Answer

Method Area

Answer

PC Register

Question 15

What happens if a superclass method is declared as final?

Accepted Answer

It cannot be overridden in a subclass

Answer

It cannot be inherited by a subclass

Answer

It can only be called once in the entire program

Answer

It must be declared as static

Question 16

What is the return type of the hashCode() method in Java Object class?

Accepted Answer

int

Answer

long

Answer

String

Answer

byte

Question 17

In constructor chaining, which statement is true regarding the super() call in a subclass constructor?

Accepted Answer

It must be the first statement in the constructor

Answer

It must be placed at the end of the constructor

Answer

It can only be used with static methods

Answer

It is only allowed in abstract classes

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Java MCQ Questions

Which of the following is NOT a Java primitive data type?

Which keyword is used by a class to inherit from another class in Java?

Which of the following is NOT a Java primitive data type?

Which of the following keywords is used to inherit a class in Java?

Which of the following is a checked exception in Java?

Which Java collection class does NOT guarantee the insertion order of elements?

Why does Java NOT support multiple inheritance through classes?

What is the default value of a local boolean variable declared inside a method in Java?

What is the default value of a local boolean variable declared inside a method in Java?

Can a Java class directly inherit multiple classes using the extends keyword?

Which of the following members of a superclass are NEVER inherited by a subclass?

Which component of the Java environment is responsible for converting bytecode into machine-specific native machine code at runtime?

Which component of the Java environment is responsible for converting bytecode into machine-specific native machine code at runtime?

Which memory area in the JVM stores newly created objects and instance variables?

What happens if a superclass method is declared as final?

What is the return type of the hashCode() method in Java Object class?

In constructor chaining, which statement is true regarding the super() call in a subclass constructor?