Real World XML

Java Is Object-Oriented from the Ground Up

We first got a look at object-oriented programming when working with JavaScript, but that was only a quick glance. Object-oriented programming is integral to every aspect of Java. For example, take a look at the application we just saw:

public class ch10_01 
{
    public static void main(String[] args)
    {
        System.out.println("Welcome to Java");
    }
}

Note the very first line, public class ch10_01, which defines a class named ch10_01. Our whole program is based on that class because, unlike in JavaScript, every line of code you write in Java has to be contained in a class (or an interface, which is a more generalized form of classes that we'll see in the next chapter). When Java runs this application, it creates ...