function groupByFirstLetter(words: string[]): Record<string, string[]> {
  let obj:Record<string,string[]> = {};

  for(let i = 0; i < words.length; i++) {
    let firstLetter = words[i][0].toLowerCase();
    let arr = [];
    
    if(!obj[firstLetter]) {
      arr.push(words[i]);
      obj[firstLetter] = arr;
    } else {
      obj[firstLetter].push(words[i])
    }
  }
  

  return obj;
}

// No modificar: necesario para evaluar el resultado.
export { groupByFirstLetter };