// APS101, Winter 2009: Lecture 7 (Jan. 22)
//
// Review: last time you started writing your own programs.
// We wrote a customized JFrame class.
// We also learned learned a lot of new terminology:

 ? What are the three types of methods?
	function: returns a data type
	constructor: creates an object and returns it
	procedure: does something, but doesn't return any data

 ? What's the difference between an argument and a parameter?
	argument: the exact value that is being passed into a method
	parameter: an abstract definition of the input that the method takes in

 ? When would you use "this"?
	"this" is used to refer to the current object.
	you put "this." in front of all instance variables and instance methods

 ? What's the process of writing a program?
	you start with a .java file, then compile it, then get .class file
	Be careful about .java~ backups!

// let's review the methods we have already written
OurJFrame ow = new OurJFrame("This is OUR JFrame!");
ow.doubleWidth()
ow.doubleWidth()
ow.getOurTitle()
// let's initialize the value of instance variable ourTitle
OurJFrame ow = new OurJFrame("This is OUR JFrame!");
ow.getOurTitle()
// let's write a 2nd constructor method & a procedure called flip()
OurJFrame ow = new OurJFrame("This is OUR JFrame!", 500, 100);
ow.flip()
// let's write a procedure called makeSquare()
OurJFrame ow = new OurJFrame("This is OUR JFrame!", 500, 100);
ow.makeSquare()
// let's write a 3rd constructor method
OurJFrame ow = new OurJFrame();
ow.getOurTitle()

// IMPORTANT RULES TO FOLLOW:
// (1) make instance variables private, unless otherwise specified
	(use public "getter" methods to access private variables)
// (2) make instance methods public, unless it's a "helper method", which is
	intended to be used only inside the class.

A a = new A();
a.x
a.x = 6;
a.x
B b = new B()
b.y

// 2 MORE IMPORTANT RULES:
// (3) always put "this." in front of all instance variables and methods
// (4) when declaring a new variable, always specify its type
       i.e., "int n = 5" vs. "n = 5"