What is static in java?

Let’s break down static in Java in the simplest possible way, step by step, and include examples to help you fully understand.

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✅ What Does static Mean in Java?

Think of static as meaning “belongs to the class, not to objects”.

In Java, you can write code that either:

• Belongs to each individual object (like someone’s name or age), or
• Belongs to the class itself, shared by all objects (like a common rule or counter). That’s where static comes in.

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🎯 Real-Life Analogy

Imagine a Car class:

• Each car object has its own color and speed (different for each car).
• But all cars share the same rule: they drive on the same road or follow the same speed limit.

We can say:

• color and speed are non-static (belong to each car).
• roadType or speedLimit is static (shared by all cars, belongs to the class).

In Java Terms

👉 1. Static Variables (a.k.a Class Variables)

public class Car {
    // static variable - shared by all Car objects
    static int numberOfCars = 0;

    // instance variable - each car has its own
    String color;

    public Car(String color) {
        this.color = color;
        numberOfCars++; // Increase count when a new Car is made
    }

    public void display() {
        System.out.println("Color: " + color);
        System.out.println("Total Cars: " + numberOfCars);
    }
}

Usage:

public class Main {
    public static void main(String[] args) {
        Car c1 = new Car("Red");
        Car c2 = new Car("Blue");

        c1.display();
        c2.display();
        // Output:
        // Color: Red, Total Cars: 2
        // Color: Blue, Total Cars: 2
    }
}

✔️ numberOfCars is static — it’s shared and keeps track of all cars.

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👉 2. Static Methods

Static methods are methods that belong to the class, not objects. You don’t need to create an object to use them.

public class MathUtil {
    public static int add(int a, int b) {
        return a + b;
    }
}

Usage:

public class Main {
    public static void main(String[] args) {
        int result = MathUtil.add(5, 3);
        System.out.println("Result: " + result); // Output: 8
    }
}

✔️ You didn’t need to write new MathUtil() — because add() is static.

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👉 3. Static Blocks

Static blocks are used to initialize static data. It runs once when the class is loaded.

public class Demo {
    static int x;

    static {
        x = 10;
        System.out.println("Static block executed");
    }
}

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👉 4. Static Classes (Nested)

You can make a static inner class (a class inside another class that doesn’t need an outer object).

public class Outer {
    static class Inner {
        public void show() {
            System.out.println("Inside static inner class");
        }
    }
}

Usage:

public class Main {
    public static void main(String[] args) {
        Outer.Inner obj = new Outer.Inner();
        obj.show();
    }
}

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🧠 Summary Table

Feature	static	Non-static
Belongs to	Class	Object
Accessed using	ClassName.member	object.member
Memory usage	One copy shared by all	Each object has its own
Example use	Utility methods, counters	Personal data like name