OBJECT ORIENTED PROGRAMMING THROUGH JAVA : Unit - 2 : Topic - 17 : Attributes: Final and Static in Java

 

Unit - 2

Topic - 17 : Attributes: Final and Static in Java

---

1. Final in Java

The final modifier can be used with variables, methods, and classes.

• Final Variables
  If a variable is declared as final, it becomes a constant.
  Once assigned, its value cannot be changed throughout the program.
  The value is usually assigned during declaration.

---

Example – Final Variable

class PhyTest {
    final int Minmarks = 35; // final variable declaration

    void run() {
        // Minmarks = 40; // ❌ This will cause a compile-time error
        System.out.println("The subject is cleared with minimum marks: " + Minmarks);
    }

    public static void main(String args[]) {
        PhyTest obj = new PhyTest();
        obj.run();
    }
}

---

Output

The subject is cleared with minimum marks: 35

---

Note:
Since Minmarks is declared as final, attempting to modify it will result in a compile-time error.

---

2. Static Methods in Java

When a method is declared as static, it becomes a class method.

• It can be called without creating an object of the class.

• Static methods belong to the class, not to individual objects.

• Static methods can only access static variables directly.

---

Example – Static Method

class Computers {
    public static void main(String args[]) {
        show(); // Calling static method without an object

        Computers obj = new Computers();
        obj.display(); // Calling instance method using an object
    }

    static void show() {
        System.out.println("Components details of computer");
    }

    void display() {
        System.out.println("Main components of computer: CPU, RAM, Storage");
    }
}

---

Output

Components details of computer
Main components of computer: CPU, RAM, Storage

---

✅ Key Points:

• final variable → Constant, cannot be modified.

• static method → Belongs to class, can be called without an object.

• Static methods can access only static variables directly.