Java MCQs

Question 1

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 2

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 3

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 4

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 5

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 6

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 7

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 8

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 9

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 10

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

Accepted Answer

int

Answer

long

Answer

String

Answer

byte

Question 11

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

Core Java Fundamentals Quiz

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Java MCQ Questions

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

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?

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

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

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 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?