Java Tutorial
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Java Control Statements
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Object Oriented Programming
- Java - OOPs Concepts
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- Java - Abstraction
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Java Built-in Classes
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Java File Handling
- Java - Files
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Java Error & Exceptions
- Java - Exceptions
- Java - try-catch Block
- Java - try-with-resources
- Java - Multi-catch Block
- Java - Nested try Block
- Java - Finally Block
- Java - throw Exception
- Java - Exception Propagation
- Java - Built-in Exceptions
- Java - Custom Exception
Java Multithreading
- Java - Multithreading
- Java - Thread Life Cycle
- Java - Creating a Thread
- Java - Starting a Thread
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- Java - Thread Scheduler
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- Java - Thread Priority
- Java - Daemon Threads
- Java - Thread Group
- Java - Shutdown Hook
Java Synchronization
- Java - Synchronization
- Java - Block Synchronization
- Java - Static Synchronization
- Java - Inter-thread Communication
- Java - Thread Deadlock
- Java - Interrupting a Thread
- Java - Thread Control
- Java - Reentrant Monitor
Java Networking
- Java - Networking
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- Java - URL Processing
- Java - URL Class
- Java - URLConnection Class
- Java - HttpURLConnection Class
- Java - Socket Class
- Java - Generics
Java Collections
Java List Interface
Java Queue Interface
Java Map Interface
- Java - Map Interface
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- Java - TreeMap
- Java - The IdentityHashMap Class
Java Set Interface
- Java - Set Interface
- Java - HashSet
- Java - EnumSet
- Java - LinkedHashSet
- Java - SortedSet Interface
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Java Data Structures
- Java - Data Structures
- Java - Enumeration
- Java - BitSet Class
- Java - Dictionary
- Java - Hashtable
- Java - Properties
Java Collections Algorithms
Advanced Java
- Java - Command-Line Arguments
- Java - Lambda Expressions
- Java - Sending Email
- Java - Applet Basics
- Java - Javadoc Comments
- Java - Autoboxing and Unboxing
- Java - File Mismatch Method
- Java - REPL (JShell)
- Java - Multi-Release Jar Files
- Java - Private Interface Methods
- Java - Inner Class Diamond Operator
- Java - Multiresolution Image API
- Java - Collection Factory Methods
- Java - Module System
- Java - Nashorn JavaScript
- Java - Optional Class
- Java - Method References
- Java - Functional Interfaces
- Java - Default Methods
- Java - Base64 Encode Decode
- Java - Switch Expressions
- Java - Teeing Collectors
- Java - Microbenchmark
- Java - Text Blocks
- Java - Null Pointer Exception
- Java - Packaging Tools
- Java - Sealed Classes
- Java - Record Classes
- Java - Hidden Classes
- Java - Compact Number Formatting
Java Miscellaneous
- Java - Recursion
- Java - Regular Expressions
- Java - Serialization
- Java - Strings
- Java - Process API Improvements
- Java - Stream API Improvements
- Java - Enhanced @Deprecated Annotation
- Java - CompletableFuture API Improvements
- Java - Array Methods
- Java - Streams
- Java - Datetime Api
- Java 8 - New Features
- Java 9 - New Features
Java APIs & Frameworks
Java Useful Resources
Java Online Quiz
Following quiz provides Multiple Choice Questions (MCQs) related to Core Java. You will have to read all the given answers and click over the correct answer. If you are not sure about the answer then you can check the answer using Show Answer button. You can use Next Quiz button to check new set of questions in the quiz.
Q 1 - What of the following is the default value of an instance variable?
Answer : C
Explaination
Instance variables are assigned default values based on their types. For example, int variable is assigned 0 and an object type variable is assigned null as default value.
Answer : B
Explaination
No, a java file can contain only one public class.
Answer : A
Explaination
int variable has default value of 0 if defined as an instance/static variable.
Answer : B
Explaination
boolean variable has default value of false if defined as an instance/static variable.
Q 5 - What is Abstraction?
A - Abstraction is a technique to define different methods of same type.
B - Abstraction is the ability of an object to take on many forms.
C - It refers to the ability to make a class abstract in OOP.
Answer : C
Explaination
It refers to the ability to make a class abstract in OOP. It helps to reduce the complexity and also improves the maintainability of the system.
Answer : A
Explaination
Holding the reference of the other class within some other class is known as composition. It represents a HAS-A relationship. For example, a Student has a Pen. Here Student class has Pen as its instance variable.
Q 7 - Method Overloading is an example of
Answer : A
Explaination
Method Overloading is example of static binding.
Q 8 - Does garbage collection guarantee that a program will not run out of memory?
Answer : B
Explaination
Garbage collection does not guarantee that a program will not run out of memory. It is possible for programs to use up memory resources faster than they are garbage collected. It is also possible for programs to create objects that are not subject to garbage collection.
Answer : B
Explaination
It is not necessary that each try block must be followed by a catch block. It should be followed by either a catch block or a finally block.
Q 10 - When finally block gets executed?
A - Always when try block get executed, no matter exception occured or not.
B - Always when a method get executed, no matter exception occured or not.
C - Always when a try block get executed, if exception do not occur.
Answer : A
Explaination
Always when try block get executed, no matter exception occured or not.
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