new Set([5, 5, 1, 5, 1])

new Set('abracadabra')

isogram = mot => mot.length == new Set(mot.toLowerCase()).size

isogram('Dermatoglyphics')

isogram('aba')

isogram('moOse')

function isogram(mot) {
  mot = mot.toLowerCase();
  for (i = 0; i < mot.length - 1; i++) {
    for (j = i + 1; j < mot.length; j++) {
      if (mot[i] == mot[j]) return false;
    }
  }
  return true;
}

isogram('Dermatoglyphics')

isogram('aba')

isogram = mot => !/(.).*\1/i.test(mot.toLowerCase())

isogram('Dermatoglyphics')