Java Tutorial
- Java - Home
- Java - Overview
- Java - History
- Java - Features
- Java vs C++
- Java Virtual Machine(JVM)
- Java - JDK vs JRE vs JVM
- Java - Hello World Program
- Java - Environment Setup
- Java - Basic Syntax
- Java - Variable Types
- Java - Data Types
- Java - Type Casting
- Java - Unicode System
- Java - Basic Operators
- Java - Comments
- Java - User Input
Java Control Statements
- Java - Loop Control
- Java - Decision Making
- Java - If-else
- Java - Switch
- Java - For Loops
- Java - For-Each Loops
- Java - While Loops
- Java - do-while Loops
- Java - Break
- Java - Continue
Object Oriented Programming
- Java - OOPs Concepts
- Java - Object & Classes
- Java - Class Attributes
- Java - Class Methods
- Java - Methods
- Java - Variables Scope
- Java - Constructors
- Java - Access Modifiers
- Java - Inheritance
- Java - Aggregation
- Java - Polymorphism
- Java - Overriding
- Java - Method Overloading
- Java - Dynamic Binding
- Java - Static Binding
- Java - Instance Initializer Block
- Java - Abstraction
- Java - Encapsulation
- Java - Interfaces
- Java - Packages
- Java - Inner Classes
- Java - Static Class
- Java - Anonymous Class
- Java - Singleton Class
- Java - Wrapper Classes
- Java - Enums
- Java - Enum Constructor
- Java - Enum Strings
Java Built-in Classes
- Java - Number
- Java - Boolean
- Java - Characters
- Java - Strings
- Java - Arrays
- Java - Date & Time
- Java - Math Class
Java File Handling
- Java - Files
- Java - Create a File
- Java - Write to File
- Java - Read Files
- Java - Delete Files
- Java - Directories
- Java - I/O Streams
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
- Java - Joining Threads
- Java - Naming Thread
- Java - Thread Scheduler
- Java - Thread Pools
- Java - Main Thread
- 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
- Java - Socket Programming
- 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
- Java - HashMap
- Java - LinkedHashMap
- Java - WeakHashMap
- Java - EnumMap
- Java - SortedMap Interface
- Java - TreeMap
- Java - The IdentityHashMap Class
Java Set Interface
- Java - Set Interface
- Java - HashSet
- Java - EnumSet
- Java - LinkedHashSet
- Java - SortedSet Interface
- Java - TreeSet
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 - static keyword
Static Variables
The static keyword is used to create variables that will exist independently of any instances created for the class. Only one copy of the static variable exists regardless of the number of instances of the class.
Static variables are also known as class variables. Local variables cannot be declared static.
Static Methods
The static keyword is used to create methods that will exist independently of any instances created for the class.
Static methods do not use any instance variables of any object of the class they are defined in. Static methods take all the data from parameters and compute something from those parameters, with no reference to variables.
Class variables and methods can be accessed using the class name followed by a dot and the name of the variable or method.
The static modifier is used to create class methods and variables, as in the following example −
Example
public class InstanceCounter { private static int numInstances = 0; protected static int getCount() { return numInstances; } private static void addInstance() { numInstances++; } InstanceCounter() { InstanceCounter.addInstance(); } public static void main(String[] arguments) { System.out.println("Starting with " + InstanceCounter.getCount() + " instances"); for (int i = 0; i < 500; ++i) { new InstanceCounter(); } System.out.println("Created " + InstanceCounter.getCount() + " instances"); } }
Output
Starting with 0 instances Created 500 instances
Following is another example, where we're accessing static method using object instead of class −
Example
public class InstanceCounter { private static int numInstances = 0; protected static int getCount() { return numInstances; } private static void addInstance() { numInstances++; } InstanceCounter() { InstanceCounter.addInstance(); } public static void main(String[] arguments) { System.out.println("Starting with " + InstanceCounter.getCount() + " instances"); for (int i = 0; i < 499; ++i) { new InstanceCounter(); } InstanceCounter ic = new InstanceCounter(); System.out.println("Created " + ic.getCount() + " instances"); } }
Output
Starting with 0 instances Created 500 instances
To Continue Learning Please Login
Login with Google