10 Pin bowling score card
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npm installto install dependencies
This project uses
Jasmine. To run the test suite, use
This project has been developed using the test-driven approach, using the RED-GREEN-REFACTOR framework.
The most important task of this project was the domain modelling as it provided much needed clarity.
ScoreCard class This will 'contain' the frames, as well as know the score of each frame. Naturally, it is able to calculate the total score of a game (on-going or completed).
Frame class The frame is aware of its rolls, as well as its score. However, as the score depends on other frames around it, it is also necessary for it to know the 'state' of other frames.
Final Frame class As the final frame in bowling has special rules, I decided to separate this out following single responsibility. This class contains the unique logic for the final frame.
Accessing the state of other frames
Frame class is instantiated along with the
ScoreCard it is a part of. This means that every instance of frame is aware of the instance of
ScoreCard it belongs to.
ScoreCard class also initializes with an array of Frames. This allows me to access
scores and other methods on other frames using
this.frames.indexOf(this) + 1 (which gives me the next frame for example).
Rules of 10 pin bowling
Bowling — how does it work?
The player has a strike if 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 would be the next frame, unless the player rolls another strike.
The player has a spare if the knocks down all 10 pins with the two rolls of a frame. The bonus for that frame is the number of pins knocked down by the next roll (first roll of next frame).
If the player rolls a strike or spare in the 10th frame they can roll the additional balls for the bonus. But they 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).
A Gutter Game is when the player never hits a pin (20 zero scores).
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 300 points.
In the image below you can find some score examples.
More about ten pin bowling here: http://en.wikipedia.org/wiki/Ten-pin_bowling