100+ Java interview questions and MCQs

Questions & Answers on Java Programming covering 100+ topics

1. Qusetions and Answers on Data Types, Variables and Arrays

The section contains questions on integer, character, floating and boolean data types, variables, type casting and conversions and properties of arrays.

Integer and Floating Data Types  Character and Boolean Data Types  Literals & Variables

Type Conversions, Promotions and Castings  Arrays

2. Questions on Operators and Control Statements

The section contains questions on arithmetic, bitwise, relational, boolean and assignment operators. The section also contains questions on control statements.

Arithmetic Operators Bitwise Operators  Relational Operators and Boolean Logic Operators

Assignment Operators and Operator Precedence  Control Statements

3. Questions and Answers on Classes and Methods

The section contains questions on fundamentals of classes, object creation, constructors, method overloading and static keyword.

Class Fundamentals & Declaring objects  Introduction to Methods  Constructors & Garbage Collection  Overloading Methods & Argument Passing

Access Control  Arrays Revisited & Keyword static  String Class

4. Questions and Answers on Inheritance and String Handling

The section contains questions on the concepts of objects, method overriding, inheritance and string handling functions like stringbuffer class and methods and other string comparison functions.

Inheritance  Method overriding  The Object Class  String Handling Basics  Character Extraction

String Comparison  Searching & Modifying a String  StringBuffer class  StringBuffer Methods

5. Questions and Answers on Packages and Interfaces

The section contains questions on packages, interfaces and various concepts of java.lang like data types, types of classes, character and byte streams.

Packages  Interfaces  Java.lang Introduction  Java.lang – Integer, Long And Character Wrappers  Java.lang – Void, Process and System Class

Java.lang – Object & Math Class  Java.io Introduction  Java.io Byte Streams Java.io Character Streams

6. Questions and Answers on Networking and Serialization

The section contains questions and answers on basics of networking, serialization and deserialization, aspects of java.util like maps, array list, hash set, tree set, linked list, stacks, vectors, dictionary and hash table. The questions under networking covers topics of URL, http response, url connection, servers, sockets and httpd class.

Serialization  Serialization & Deserialization  Networking Basics  URL class  HttpResponse & URLConnection Class  networking – Server, Sockets & httpd Class  networking – httpd.java Class  networking – Datagrams

Java.util – ArrayList Class  Java.util – LinkedList, HashSet & TreeSet Class  Java.util – Maps  Java.util – Array Class  Java.util – Vectors & Stack  Java.util – Dictionary, Hashtable & Properties  Java.util – BitSet & Date class

7. Questions on Exception Handling

The section contains questions on basics of exception handling, exception types like throw, throws and nested try.

Methods Taking Parameters  Exceptional Handling Basics

Exceptions Types  Throw, Throws & Nested Try

8. Questions and Answers on Multithreading

The section contains questions and answers on basics of multithreading, thread basics, thread creation, isAlive(), join() and thread synchronization basics.

isAlive(), Join() & Thread Synchronization Implementing Runnable interface for Threads  Thread class  Multithreading Basics

Networking Basics  Finally & Built in Exceptions  Creating Threads

9. Questions on I/O

The section contains questions and answers on basics of I/O, file reading and writing and reading console i/p and writing console o/p.

Input & Output Basics  Reading Console Input

Writing Console Output  Reading & Writing Files

10. Questions and Answers on Applets

The section contains questions on fundamentals of applets, RMI and java API packages.

Applets Fundamentals  Core Java API Packages

Remote Method Invocation (RMI)  Text Formatting

11. Questions on Event Handling

The section conatins questions on basics of event handling, different types of event handling classes like actionevent, componentevent, containerevent, textevent, mouseevent, windowevent and other event listener interfaces.

Event Handling Basics  ActionEvent & AdjustmentEvent Class  ComponentEvent, ContainerEvent & FocusEvent Class

MouseEvent, TextEvent & WindowEvent Class  Event Listeners Interfaces

12. Questions and Answers on Java.lang Package

The section contains questions on classes, methods, functions and wrappers of java.lang package. These include rounding functions, math methods, byte, short, double and float wrappers and runtime and classloader classes.

Java.lang – Rounding Functions  Java.lang – Miscellaneous Math Methods & StrictMath Class  Java.lang – ThreadGroup class & Runnable Interface  Java.lang – System Class Advance  Java.lang – Double & Float Wrappers  Java.lang – Byte & Short Wrappers  Java.lang – Character Wrapper Advance

Java.lang – Boolean Wrapper Advance  Java.lang – Runtime & ClassLoader Classes  java.lang – Class

13. Questions and Answers on Collection Framework

The section contains questions on collection interface and algorithms, iterators and command line arguments, locale, random, observable and timer classes, generic methods and type interfaces.

Collection Framework Overview  Collections Interface  Collection Algorithms  Iterators  Locale & Random Classes  Observable & Timer Class  Restrictions On Generics  Wildcards

Recursion Command Line Arguments  Inheritance – Abstract Class and Super  Try & Catch  Creating Exceptions  Generics  Generic Methods Type Interface

If you would like to learn Java Programming thoroughly, you should attempt to work on the completeset of Java questions and answers mentioned above. It will immensely help anyone trying to crack Java Programming or an interview.