Variables

📊 Variables in Java

In Java, variables are used to store data that can be used later in the program. Each variable has a data type and is associated with a name that can be used to reference the value it holds.

🧠 Types of Variables in Java

1. Instance Variables

   • Declared inside a class but outside any method.
   • Associated with an object instance.

2. Local Variables

   • Declared inside a method, constructor, or block.
   • Exist only within the scope of the method/block.

3. Static Variables (Class Variables)

   • Declared with the static keyword.
   • Shared among all instances of the class.

4. Final Variables

   • Declared with the final keyword.
   • Cannot be changed once assigned a value.

🧪 Example: Different Types of Variables

public class VariablesExample {
    int instanceVar = 10; // instance variable

    public void exampleMethod() {
        int localVar = 20;  // local variable
        System.out.println("Local Variable: " + localVar);
        System.out.println("Instance Variable: " + instanceVar);
    }

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

🚨 Important Notes

• Default Values: Variables in Java are assigned default values if not explicitly initialized. For example, int defaults to 0, and boolean defaults to false.
• Final Variables: Once assigned, final variables cannot be modified.

🔗 Related Notes

• Data Types
• Operators
• Program Control Statements
• Arrays
• Strings