https://www.codewars.com/kata/546f922b54af40e1e90001da/train/javascript

kata.js

function alphabetPosition(text) {
  const alphabet = 'abcdefghijklmnopqrstuvwxyz'.split('')
  const letters = text.replace(/\s/g, '').split('');
  const numbers = [];
  
  letters.forEach(letter => {
    letter = letter.toLowerCase();
    
    alphabet.find((value, index) => {
      if (value === letter) {
        numbers.push(index + 1)
      }
    });
  })
  
  return numbers.join(' ');
}