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## to Scrabble Score in the Ruby Track

Published at Jul 13 2018 · 1 comment
Instructions
Test suite
Solution

Given a word, compute the scrabble score for that word.

## Letter Values

You'll need these:

``````Letter                           Value
A, E, I, O, U, L, N, R, S, T       1
D, G                               2
B, C, M, P                         3
F, H, V, W, Y                      4
K                                  5
J, X                               8
Q, Z                               10
``````

## Examples

"cabbage" should be scored as worth 14 points:

• 3 points for C
• 1 point for A, twice
• 3 points for B, twice
• 2 points for G
• 1 point for E

And to total:

• `3 + 2*1 + 2*3 + 2 + 1`
• = `3 + 2 + 6 + 3`
• = `5 + 9`
• = 14

## Extensions

• You can play a double or a triple letter.
• You can play a double or a triple word.

For installation and learning resources, refer to the exercism help page.

For running the tests provided, you will need the Minitest gem. Open a terminal window and run the following command to install minitest:

``````gem install minitest
``````

If you would like color output, you can `require 'minitest/pride'` in the test file, or note the alternative instruction, below, for running the test file.

Run the tests from the exercise directory using the following command:

``````ruby scrabble_score_test.rb
``````

To include color from the command line:

``````ruby -r minitest/pride scrabble_score_test.rb
``````

## Source

Inspired by the Extreme Startup game https://github.com/rchatley/extreme_startup

## Submitting Incomplete Solutions

It's possible to submit an incomplete solution so you can see how others have completed the exercise.

### scrabble_score_test.rb

``````require 'minitest/autorun'
require_relative 'scrabble_score'

class ScrabbleTest < Minitest::Test
def test_empty_word_scores_zero
assert_equal 0, Scrabble.new('').score
end

def test_whitespace_scores_zero
skip
assert_equal 0, Scrabble.new(" \t\n").score
end

def test_nil_scores_zero
skip
assert_equal 0, Scrabble.new(nil).score
end

def test_scores_very_short_word
skip
assert_equal 1, Scrabble.new('a').score
end

def test_scores_other_very_short_word
skip
assert_equal 4, Scrabble.new('f').score
end

def test_simple_word_scores_the_number_of_letters
skip
assert_equal 6, Scrabble.new('street').score
end

def test_complicated_word_scores_more
skip
assert_equal 22, Scrabble.new('quirky').score
end

def test_scores_are_case_insensitive
skip
assert_equal 41, Scrabble.new('OXYPHENBUTAZONE').score
end

def test_convenient_scoring
skip
assert_equal 13, Scrabble.score('alacrity')
end
end``````
``````class Scrabble
SCORING = {
A: 1,   B: 3,   C: 3,   D: 2,   E: 1,   F: 4,   G: 2,   H: 4,   I: 1,
J: 8,   K: 5,   L: 1,   M: 3,   N: 1,   O: 1,   P: 3,   Q: 10,  R: 1,
S: 1,   T: 1,   U: 1,   V: 4,   W: 4,   X: 8,   Y: 4,   Z: 10
}

SCORE = ->(letter) { SCORING[letter.to_sym] }

def initialize(word)
@word = word.is_a?(String) ? normalize(word) : ''
end

def self.score(word)
new(word).score
end

def score
@word.chars.map(&SCORE).inject(0, :+)
end

private

def normalize(word)
word.upcase.gsub(/[^A-Z]/,'')
end
end``````

## Community comments

Find this solution interesting? Ask the author a question to learn more. Solution Author
commented about 5 years ago

It would be more readable to provide the scoring as a hash with points as keys and arrays of letters as values. I decided on a hash with letters as keys and points as values firstly to avoid having to search an array when looking up the score for a letter, and secondly to be able to order the letters alphabetically so that it is easy to spot if a letter is missing.

### What can you learn from this solution?

A huge amount can be learned from reading other people’s code. This is why we wanted to give exercism users the option of making their solutions public.

Here are some questions to help you reflect on this solution and learn the most from it.

• What compromises have been made?
• Are there new concepts here that you could read more about to improve your understanding?