Rules for Declaring Methods

A method must be declared inside a class and must have a valid return type, name, parameter list, and body.

Example 1: A Valid Method Declaration

class MethodRulesDemo {
    // Method name uses camelCase
    static int calculateTotal(int price, int quantity) {
        return price * quantity;
    }

    public static void main(String[] args) {
        System.out.println(calculateTotal(50, 3));
    }
}

Important Method Rules

• A method must be declared inside a class.
• The number, types, and order of arguments in a call must match the method parameters.
• A method with a non-void return type must return a matching value.
• A void method cannot return a value.
• Overloaded methods must have different parameter lists.

Example 2: Matching Arguments with Parameters

class MethodRulesDemo {
    static void displayAge(String name, int age) {
        System.out.println(name + " is " + age + " years old.");
    }

    public static void main(String[] args) {
        displayAge("Simran", 24);
    }
}

Best Practices

These habits make methods easier to understand and reuse.

• Use a meaningful name, such as calculateTotal() or displayMessage().
• Keep one method focused on one clear task.
• Use parameters instead of relying on fixed values inside a method.
• Break a long or complex task into smaller methods.
• Choose a return type that matches the result the method should provide.

Example 3: One Method, One Task

class MethodRulesDemo {
    static void displayWelcomeMessage() {
        System.out.println("Welcome to ShikshaSanchar");
    }

    public static void main(String[] args) {
        displayWelcomeMessage();
    }
}

Chapter Summary: