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# PatrickMcSweeny's solution

## to Resistor Color in the JavaScript Track

Published at Aug 28 2019 · 0 comments
Instructions
Test suite
Solution

#### Note:

This exercise has changed since this solution was written.

Resistors have color coded bands, where each color maps to a number. The first 2 bands of a resistor have a simple encoding scheme: each color maps to a single number.

These colors are encoded as follows:

• Black: 0
• Brown: 1
• Red: 2
• Orange: 3
• Yellow: 4
• Green: 5
• Blue: 6
• Violet: 7
• Grey: 8
• White: 9

Mnemonics map the colors to the numbers, that, when stored as an array, happen to map to their index in the array: Better Be Right Or Your Great Big Values Go Wrong.

More information on the color encoding of resistors can be found in the Electronic color code Wikipedia article

## 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

Maud de Vries, Erik Schierboom https://github.com/exercism/problem-specifications/issues/1458

## Submitting Incomplete Solutions

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

### resistor-color.spec.js

``````import { colorCode, COLORS } from './resistor-color'

describe('ResistorColor', () => {
describe('Color codes', () => {
test('Black', () => {
expect(colorCode("black")).toEqual(0)
})

xtest('White', () => {
expect(colorCode("white")).toEqual(9)
})

xtest('Orange', () => {
expect(colorCode("orange")).toEqual(3)
})
})

xtest('Colors', () => {
expect(COLORS).toEqual(["black","brown","red","orange","yellow","green","blue","violet","grey","white"])
})
})``````
``````export const COLORS = ["black", "brown", "red", "orange", "yellow", "green", "blue", "violet", "grey", "white"];

export const colorCode = (color) => {
return COLORS.indexOf(color);
};``````

## Community comments

Find this solution interesting? Ask the author a question to learn more.

### What can you learn from this solution?

A huge amount can be learned from reading other peopleโ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?