alphaIndex.js

// Replace with Alphabet Position from http://www.codewars.com/kata/546f922b54af40e1e90001da/train/javascript

/*Welcome.

In this kata you are required to, given a string, replace every letter with its position in the alphabet.

If anything in the text isn't a letter, ignore it and don't return it.

a being 1, b being 2, etc.

As an example:

alphabet_position("The sunset sets at twelve o' clock.")
Should return "20 8 5 19 21 14 19 5 20 19 5 20 19 1 20 20 23 5 12 22 5 15 3 12 15 3 11" as a string.*//*eslint-disable*/

// const alphabetPosition = text => {
//   const alphabet = 'àabcdefghijklmnopqrstuvwxyz';
//   return [...`${text.toLowerCase()}`].reduce((indices, letter) => [...indices, alphabet.indexOf(letter)], []).filter(i => i > 0).join` `;
// };

alphabetPosition=t=>(a='àabcdefghijklmnopqrstuvwxyz',[...`${t.toLowerCase()}`].reduce((i,l)=>[...i,a.indexOf(l)],[]).filter(i=>i>0).join` `)

alphabetPosition=t=>[...t].map(l=>l.toLowerCase().charCodeAt(0)-96).filter(i=>i>0).join` `

alphabetPosition=t=>t.match(/[a-zA-Z]/g).map(l=>l.toLowerCase().charCodeAt()-96).join` `

alphabetPosition=t=>t.toLowerCase().match(/[a-z]/g).map(l=>l.charCodeAt()-96).join` `

const {expect} = require('chai');

describe('alphabetPostion function', () => {
  it('should convert letters to their position in the alphabet', () => {
    expect(alphabetPosition('The sunset sets at twelve o\' clock.')).to.equal('20 8 5 19 21 14 19 5 20 19 5 20 19 1 20 20 23 5 12 22 5 15 3 12 15 3 11');
    expect(alphabetPosition('The narwhal bacons at midnight.')).to.equal('20 8 5 14 1 18 23 8 1 12 2 1 3 15 14 19 1 20 13 9 4 14 9 7 8 20');
  });
});