Defining and Calling Methods

What is a Method? A method is a block of code that performs a specific task. It runs only when it is called. You can pass data, known as parameters, into a method.

Why Use Methods?

• Reusability: Write the code once and use it many times.

• Organization: Break down complex problems into smaller, manageable pieces.

• Readability: Well-named methods make your code easier to understand.

Anatomy of a Method Definition:

• Access Modifier: (e.g., public) - Who can call this method?

• static (optional): If present, the method belongs to the class, not an object.

• Return Type: The data type of the value the method returns (e.g., int, String, or void if it returns nothing).

• Method Name: A descriptive name for the method (e.g., calculateSum).

• Parameters: A list of variables passed into the method, enclosed in parentheses ().

• Method Body: The code to be executed, enclosed in curly braces {}.

Calling a Method: To execute a method, you simply write its name followed by parentheses, providing any required arguments: int sum = calculateSum(10, 20);

The return Keyword: If a method has a return type other than void, its body must end with a return statement that provides a value of that type.

Mini-Exercise: Create a method named greetUser that takes a String (a name) as a parameter and prints a personalized greeting, like "Hello, [Name]!". Call this method from your main method with your name.

public class Calculator {
    public static void main(String[] args) {
        // Call the add method and store the result
        int result = add(5, 10);
        System.out.println("The sum is: " + result); // The sum is: 15
    }

    // Method definition
    public static int add(int num1, int num2) {
        int sum = num1 + num2;
        return sum; // Return the result
    }
}