Creating a Child Class

Here is a more detailed description for the basic syntax to use when creating a Java class:


class ClassName extends ParentClass
{
    private Class instanceVariable;
    ...
    public ClassName()
    {
        statement;
        ...
    }
    public returnType methodName(class arg1, ...)
    {
        statement;
        ...
    }
}

If you create a class that does not specify its superclass, it automatically is defined as a subclass of the Object class.
So, all of your applications have as their parent the default (Object) and your graphical classes have JPanel as their parent.
This is why our graphical classes already have some methods available to them - they inherit them from the parent JPanel class.
Let's look at RunLight.java again.