placing text on the canvas
programming techniques for representing information
programming a pause
calculating elapsed time
one method of shuffling a set of card objects
This chapter demonstrates two versions of a card game known variously as memory or concentration. Cards appear face down, and the player turns over two at a time (by clicking on them) in an attempt to find matched pairs. The program removes matches from the board but [virtually] flips back cards that do not match. When players make all the matches, the game shows the elapsed time.
The first version of the game ...