Java Methods

Java Methods

A method is a block of code that runs only when it is called. You can pass data, known as parameters, into a method. Methods are used to perform certain actions, and they are also known as functions.

Why use methods? To reuse code: define the code once, and use it many times.

Creating a Method

A method must be declared within a class. It is defined with the name of the method, followed by parentheses (). Java provides some pre-defined methods, such as System.out.println(), but you can also create your own methods to perform certain actions.

public class Main {
  // This is a static method
  static void myMethod() {
    // The body of the method
    System.out.println("I just got executed!");
  }

  public static void main(String[] args) {
    // Method is called here
    myMethod();
  }
}

Method Breakdown:

• myMethod() is the name of the method.
• static means that the method belongs to the Main class and not an object of the Main class. You will learn more about objects and how to access methods through objects later in this tutorial.
• void means that this method does not have a return value. You will learn more about return values in the next chapter.

Calling a Method

To call a method, you write the method's name followed by two parentheses () and a semicolon ;.

In the following example, myMethod() is used to print a text (the action) when it is called.

public class Main {
  static void myMethod() {
    System.out.println("Hello from myMethod!");
  }

  public static void main(String[] args) {
    myMethod(); // Call the method
    myMethod(); // Call it again
    myMethod(); // And again
  }
}