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Java Program - Using Methods (setValue)

Concept Explanation

What is it?

Methods are blocks of code that perform a specific task. A setValue method (often called a "setter") is used to assign values to class fields after an object has been created.

Why is it important?

It promotes modularity. Instead of putting all logic in main, you separate data assignment into dedicated methods.

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Implementations

Java (JDK 17)

class Car {
    String model;
    int year;

    // Method to set values
    void setValues(String m, int y) {
        model = m;
        year = y;
    }

    void display() {
        System.out.println("Car Model: " + model);
        System.out.println("Year:      " + year);
    }
}

public class MethodDemo {
    public static void main(String[] args) {
        Car myCar = new Car();
        
        // Calling the method
        myCar.setValues("Toyota Camry", 2022);
        
        myCar.display();
    }
}

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Explanation

• Parameters: String m and int y are local variables.
• Assignment: Inside the method, model = m copies the value from the parameter to the instance variable.
• Separation: This approach separates creation (new Car()) from initialization (setValues).

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Related Concepts

• Using Constructors (Alternative way to initialize)
• Encapsulation (Using setters with validation)