#37 Static Variable in JAVA | Skyhighes | Lecture 37

Here's a comprehensive explanation of static variables in Java:

What are static variables?

Class variables: They belong to the class itself, rather than individual objects of the class.
Shared across all objects: Only one copy of a static variable exists, shared by all instances of the class.
Declared with static keyword: Use the static keyword to create a static variable within a class.
Key characteristics:

Memory allocation: Allocated in static memory when the class is loaded, not when objects are created.
Lifetime: Exist throughout the entire program's execution, even if no objects of the class exist.
Access: Can be accessed directly using the class name (e.g., ClassName.staticVariable) or through objects of the class.
Initialization: Can be initialized either directly in their declaration or within a static block.
Example:

Java
class Counter {
static int count = 0; // Static variable

public Counter() {
count++; // Increment count for each object created
}

public static void displayCount() {
System.out.println("Total objects created: " + count);
}
}
Use code with caution. Learn more
Common uses:

Constants: Used to define constants that are shared across the entire application (e.g., Math.PI, Integer.MAX_VALUE).
Counting objects: Keeping track of the number of objects created for a class (as in the example above).
Shared resources: Managing shared resources like database connections or file handles.
Utility classes: Creating utility classes that provide general-purpose functions without the need for object instantiation.
Best practices:

Use static variables judiciously, as overuse can lead to tight coupling and maintainability issues.
Be mindful of thread safety when using static variables in multithreaded environments.
Consider using static factory methods or dependency injection as alternatives for accessing shared resources.
Always initialize static variables to avoid unexpected behavior.