Lesson 4: Methods

This lesson explains how to define and call methods, pass arguments, return values, pass arrays, and overload methods.

A method is a named block of code that performs a specific task. In procedural languages, similar blocks may be called procedures, functions, or subroutines. In Java, they are called methods.

Methods help make programs easier to read, test, and reuse.

A method header usually contains:

Example:

public static void greet() {
    System.out.println("Welcome!");
}

A method can receive values through parameters. The values sent during the method call are called arguments.

The number and type of arguments in the call must match the method's parameter list.

A method can send a value back to the statement that called it. The method's return type must match the returned value.

public static int square(int x) {
    return x * x;
}

A void method does not return a value.

A static method belongs to a class. It can be called inside its own class using its name, or from another class using the class name followed by a dot.

Utility.greet();

The class containing the method must be compiled and available to the other class.

An entire array can be passed to a method by using the array name without brackets.

When an array is passed to a method, the method receives access to the same array object. Changes made to the array elements inside the method affect the original array.

Method overloading means creating multiple methods with the same name but different parameter lists. The compiler chooses which method to run based on the arguments used.

Methods can differ by:

• number of parameters
• parameter types
• parameter order

Return type alone is not enough to overload a method.

Call the methods with different arguments and try writing your own method below main.