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My Intro to Object-Oriented Programming

Class Notes
Wednesday October 11 , 2000

The main topic of tonight's lecture was the ' Functional Application Architecture'. The functional application architecture is the application architecture in which:

All variables referenced in a method are declared local to the method.
All methods defined in the class, with the exception of the ``main'' method, are operators.

Here is an example of the functional approach:

A line of n-congruent squares collectively has area a. What is the perimeter of the line of squares?

class LineOfSquaresFAA
static public void main (~ ~ ~ ~ ~ ~)
{

double figureArea = readFigureArea ();
int nrSquares = readNrOfSquares ();
double squareArea = computeSquareArea (figureArea, nrSquares);
double squareSide = computeSquareSide (squareArea);
int eeCount = computeEECount (nrSquares);
double perimeter = computePerimeter (squareSide, eeCount);
IO.println (``Perimeter = ``+ perimeter);

} / /End of main method.
static private double readFigureArea ()
{

IO.print (``Area of figure? '');
return IO.read_double ();
}
static private int readNrOfSquares ()
{
IO.print (``How many squares? '');
int nrOfSquares = IO.read_int ();
return nrSquares;
}
static private double computeSquareArea (double totalArea, int nrSquares)
{
double sa = totalArea /nrSquares;
return sa;
}
static private double computeSquareSide (double areaOfSquare)
{
return Math.sqrt (areaOfSquare);
}
static private int computeEECount (int ns)
{
return (ns * 2) + 2;
}
static private double perimeter (double s, int eeCount)
{
return s * eeCount;
}

CG gave a defintion for the objective application architecture, but I have chosen to include it in the notes for October 16, 2000..