const isIsogram = str => {
str = str.toLowerCase().split('')
let dupArr = [...new Set(str)]
return dupArr.join('').length === str.join('').length
}
console.log(isIsogram("Dermatoglyphics"))// An isogram is a word that has no repeating letters, consecutive or non-consecutive. Implement a function that determines whether a string that contains only letters is an isogram. Assume the empty string is an isogram. Ignore letter case.
const isIsogram = str => {
str = str.toLowerCase().split('')
let dupArr = [...new Set(str)]
return dupArr.join('').length === str.join('').length
}
console.log(isIsogram("Dermatoglyphics"))
// With love @kouqhar