Class Variables vs Instance Variables in Java (With Examples)

Understand the key difference between class variables (static) and instance variables in Java. Learn when to use them with beginner-friendly examples.

📌 Overview

In Java, variables declared inside a class can be:

• Class Variables (also called static variables)
• Instance Variables (also called non-static variables)

They look similar, but they behave very differently.

🧬 Instance Variables (Non-Static)

• Declared inside a class, but outside any method
• Belongs to each object (instance) of the class
• Each object has its own copy

✅ Example:

public class Student {
    String name; // instance variable

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

Student s1 = new Student("Amit");
Student s2 = new Student("Ravi");

System.out.println(s1.name); // Amit
System.out.println(s2.name); // Ravi

➡️ Changing s1.name will not affect s2.name.

🌐 Class Variables (Static)

• Declared with the keyword static
• Belongs to the class itself, not to objects