No conditional statements Polymorphism/Object heavy TDD As If You Meant It
Classes can be no longer than one hundred lines of code. Methods can be no longer than five lines of code. Pass no more than four parameters into a method. Hash options are parameters.
The Three Questions What, if anything, did you learn today? What, if anything, surprised you today? What, if anything, will you do differently in the future?
The game consists of 10 frames as shown above. In each frame the player has two opportunities to knock down 10 pins. The score for the frame is the total number of pins knocked down, plus bonuses for strikes and spares.
A spare is when the player knocks down all 10 pins in two tries. The bonus for that frame is the number of pins knocked down by the next roll. So in frame 3 above, the score is 10 (the total number knocked down) plus a bonus of 5 (the number of pins knocked down on the next roll.)
A strike is when the player knocks down all 10 pins on his first try. The bonus for that frame is the value of the next two balls rolled.
In the tenth frame a player who rolls a spare or strike is allowed to roll the extra balls to complete the frame. However no more than three balls can be rolled in tenth frame.
Write a class named “Game” that has two methods roll(pins : int) is called each time the player rolls a ball. The argument is the number of pins knocked down. score() : int is called only at the very end of the game. It returns the total score for that game.
Bowling Game green belt: intermediate
Count and sum the scores of a bowling game of one player.
A bowling game consists of 10 frames in which the player tries to knock down the 10 pins. In every frame the player can throw one or two times. The actual number depends on strikes and spares. The score of a frame is the number of knocked down pins plus bonuses for strikes and spares. After every frame the 10 pins are resettet.
Strikes
The player has a strike of he knocks down all 10 pins with the first roll in a frame. The frame ends immediately (since there are no pins left for a second roll). The bonus for that frame is the number of pins knocked down by the next two rolls. That is the next frame, except if the player rolls a strike again.
Spares
The player has a spare if the knocks down all 10 pins with the two roles of a frame. The bonus for that frame is the number of pins knocked down by the next roll (first role of next frame).
10th frame
If the player rolls a strike or spare in the 10th frame he can roll the additional balls for the bonus. But he can never roll more than 3 balls in the 10th frame. The additional rolls only count for the bonus not for the regular frame count.
10, 10, 10 in the 10th frame gives 30 points (10 points for the regular first strike and 20 points for the bonus) 1, 9, 10 in the 10th frame gives 20 points (10 points for the regular spare and 10 points for the bonus) Gutter Game
A Gutter Game is when the player never hits a pin (20 zero scores).
Perfect Game
A Perfect Game is when the player rolls 12 strikes (10 regular strikes and 2 strikes for the bonus in the 10th frame). The Perfect Game scores to 300 points.
Example score
Frame Roll Knocked-down-pins Total-score Notes 1 1 1 1 2 4 5 2 1 4 2 2 5 14 3 1 6 3 2 4 29 Spare: 10 pins plus bonus of 5 from next roll (roll 1 of frame 4) 4 1 5 4 2 5 49 Spare: 10 pins plus bonus of 10 from next roll (roll 1 frame 5) 5 1 10 Strike 5 2 60 Strike: 10 pins plus bonus of 1 from next frame (rolls 1 and 2 from frame 6) 6 1 0 Bad luck 6 2 1 61 7 1 7 7 2 3 77 Spare 8 1 6 8 2 4 97 Spare 9 1 10 Strike 9 2 117 10 1 2 10 2 8 Spare 10 3 6 133 Extra roll due to spare in 10th frame
Write a class BowlingGame with two methods
- roll(pins : int)
- score() : int
For every roll the roll method is called. The score method returns the total score.
Test cases
see table with example game
References
The kata was described originally by Robert Martin (see original description). Wikipedia article with the scoring rules: http://en.wikipedia.org/wiki/Ten-pin_bowling#Scoring
http://elegantcode.com/2014/01/02/clojure-kata-2-the-bowling-game/