Static Keyword

❔ What is static in Java?

The static keyword is used to create class-level members, meaning they belong to the class itself, not individual objects.

It can be applied to:

• Variables

• Methods

• Blocks

• Nested classes

💡 Real-Life Analogy

• Think of a school name shared by all students.

• You don’t need to store it for each student — it's common.

That’s exactly what static does — shares the same data across all objects.

🔗 Static Variable

A static variable is shared among all instances of a class.

class Student {
    static String school = "Greenwood High";  // shared

    String name;

    Student(String name) {
        this.name = name;
    }

    void display() {
        System.out.println(name + " from " + school);
    }
}

public class Main {
    public static void main(String[] args) {
        Student s1 = new Student("Aanya");
        Student s2 = new Student("Rahul");

        s1.display();
        s2.display();
    }
}

Aanya from Greenwood High
Rahul from Greenwood High

✅ Both objects access the same static variable school.

📌 Static Method

A static method can be called without creating an object of the class.

class Utility {
    static void greet() {
        System.out.println("Hello from static method!");
    }
}

public class Main {
    public static void main(String[] args) {
        Utility.greet();  // no object needed
    }
}

Hello from static method!

⚠️ Rules of Static Methods

• Can only access static variables/methods directly

• Cannot use this or super

• Best for utility/helper methods (like Math.sqrt())

🧱 Static Block

A static block is executed ****only once, when the class is first loaded.

class Demo {
    static {
        System.out.println("Static block called");
    }

    public static void main(String[] args) {
        System.out.println("Main method");
    }
}

Static block called
Main method

✅ Recap Table