Static Variables and Methods

Understanding Static Variables

Static variables, also known as class variables, are variables that belong to a class, not instances of the class.
They are initiated when the class is loaded and persist throughout the entire execution of the program.
All instances of the class share the same copy of static variables. Any changes made to a static variable are reflected across all instances of the class.
Static variables are declared using the static keyword before the data type of the variable.

Using Static Variables

Static variables are useful when you want to maintain a common state among all the instances of a class.
They can be accessed directly using the class name, without the need to create an instance of the class.
Static variables can be used to track information that should be shared among all instances of a class, such as a counter that keeps track of the number of instances created.

Understanding Static Methods

Static methods are methods that belong to a class, not to instances of the class.
Like static variables, they can be called using the class name rather than an instance of the class.
They can only directly access static variables and other static methods, but cannot access instance variables or instance methods.

Using Static Methods

Static methods are often used to perform operations that don’t need to access any instance variables.
One common use of static methods is in the creation of utility classes, where a class simply groups together methods that perform related tasks.
In a static method, you can modify static variables but you can’t access non-static variables of the class.
main method is the most common example of a static method in Java.

By understanding the usage and restrictions of static variables and methods, one can significantly improve efficiency and readability of the Java code.