why we assign firefoxdriver instance to webdriver

Question

I am novice to Java or Selenium.

I just need help to understand one basic question.

Why we assign firefoxdriver instance to WebDriver? WebDriver driver=new Firef

Answer 1

The Answer is simple,

WebDriver is an interface which has a common behavior and we upcast so that the same behavior can be used across the Classes. Example:

Interface: Consider WebDriver has the behavior of Switch

public interface WebDriver

{

void on();

void off();

int voltage=220;;

}

Class1: Consider this as ChromeDriver class

public class ChromeDriver implements WebDriver {

@Override
public void on() {
    System.out.println("ChromeDriver On");

}

@Override
public void off() {
System.out.println("ChromeDriver Off");

}

} Class 2: Consider this class as FireFoxDriver class

public class FireFoxDriver implements WebDriver {

@Override
public void on() {
    System.out.println("FireFoxDriver On");

}

@Override
public void off() {
System.out.println("FireFoxDriver Off");

}

}

Now Consider Runner Class:

//Here to change the implementation we just need to change the object
    //Whether you need to access Mozilla or Chrome

public class Runner {

 Webdriver driver = new ChromeDriver();//new FireFoxDriver();
 driver.on();
 driver.off();``

}