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PatrickMcSweeny's solution

to Scrabble Score in the JavaScript Track

Published at Aug 24 2019 · 0 comments
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.

Setup

Go through the setup instructions for Javascript to install the necessary dependencies:

https://exercism.io/tracks/javascript/installation

Requirements

Install assignment dependencies:

$ npm install

Making the test suite pass

Execute the tests with:

$ npm test

In the test suites all tests but the first have been skipped.

Once you get a test passing, you can enable the next one by changing xtest to test.

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.spec.js

import { score } from './scrabble-score';

describe('Scrabble', () => {
  test('lowercase letter', () => {
    expect(score('a')).toEqual(1);
  });

  xtest('uppercase letter', () => {
    expect(score('A')).toEqual(1);
  });

  xtest('valuable letter', () => {
    expect(score('f')).toEqual(4);
  });

  xtest('short word', () => {
    expect(score('at')).toEqual(2);
  });

  xtest('short, valuable word', () => {
    expect(score('zoo')).toEqual(12);
  });

  xtest('medium word', () => {
    expect(score('street')).toEqual(6);
  });

  xtest('medium, valuable word', () => {
    expect(score('quirky')).toEqual(22);
  });

  xtest('long, mixed-case word', () => {
    expect(score('OxyphenButazone')).toEqual(41);
  });

  xtest('english-like word', () => {
    expect(score('pinata')).toEqual(8);
  });

  xtest('empty input', () => {
    expect(score('')).toEqual(0);
  });

  xtest('entire alphabet available', () => {
    expect(score('abcdefghijklmnopqrstuvwxyz')).toEqual(87);
  });
});
const LETTERS = {
  1: /A|E|I|O|U|L|N|R|S|T/gi,
  2: /D|G/gi,
  3: /B|C|M|P/gi,
  4: /F|H|V|W|Y/gi,
  5: /K/gi,
  8: /J|X/gi,
  10: /Q|Z/gi
};

export const score = word => {
  return Object.keys(LETTERS)
    .map(key => {
      return numberOfMatches(word, LETTERS[key]) * key;
    })
    .reduce((sum, number) => sum + number);
};

export const numberOfMatches = (word, regex) => {
  let matches = word.match(regex);

  return matches !== null ? matches.length : 0;
};

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