Tutorial 6 (Feb 4): Classes continued, UML

Outline

We will go over the following concepts again from last class:

• Class declaration
• Constructors
• Instance methods (sending messages to objects)
• Instance variables
• Creating objects using the new operator

In-class exercise

The GradeSimulator example last class may have been a little difficult to grasp at the beginning. We will work on a simpler example today called Banking, and I will leave GradeSimulator as an example for your reference.

Download Banking: Handout || Solution || Javadoc (there is no exercise code, we'll start from scratch in class)
Download GradeSimulator: Handout || Exercise || Solution || Javadoc

Other material for reference:

• The supplement slides I made on Classes covers (Revised Feb 6):
  • Important! I made a mistake on the last slide using this() as a constructor. The correct way is "this(0, 0" and not "this.Point(0, 0)", sorry about that! (Thanks Lisa for catching that.)
  • main() function
  • constructors
  • class vs instance
    • instance methods
    • instance variables
    • class methods
    • class variables
    • access control
    • this keyword
• Refer to Tutorial 5 (Feb 2) for how to generate Javadoc
• The examples involving DateTime in Chapter 4 of your textbook.
• This simple game I made, still undocumented.
• UML diagram basics by Beck Hasti @ WISC

The Math class

For Assignment 2, you may need to use the following methods from the Math class:

Math.pow(double baseNumber, double exponent)
double someNumber = 5;
double someNumberSquared = Math.pow(someNumber, 2); //25

Math.sqrt(double numberToSqrt)
double anotherNumber = 25;
double sqrtOfAnotherNumber = Math.sqrt(anotherNumer); //5