learn-co-curriculum / java-mod-2-drivers

Driver Class

Learning Goals

• Discuss what a Driver class is in Java

What is a Driver?

Sometimes in Java, when we want to bring multiple classes together to instantiate and call actions, we will create a driver or runner class. A driver class is often just a class with a main() method so that it can be made runnable in Java. We can import numerous classes to instantiate and execute various methods to "drive" or "run" the program.

In the Inheritance lesson, we used a class Main to demonstrate how the Cat and the Parrot classes were children of the Animal class, like so:

package com.flatiron.animal;

public class Main {
   public static void main(String[] args) {
      Cat tom = new Cat();
      tom.setName("Tom");
      System.out.println("Hello! My name is " + tom.getName());
      tom.eat();
      tom.useLitter();

      Parrot polly = new Parrot();
      System.out.println("I'm a parrot and my name is " + polly.getName());
      polly.eat();
      polly.startFlying();
   }
}

Notice how the only purpose of the Main class was to instantiate our Cat and Parrot instances and call on their methods. This is an example of a driver class.