js check string for isogram
// Check if a string is an isogram
function isIsogram(str){
return !str.match(/([a-z]).*\1/i);
//or: return new Set(str.toLowerCase()).size === str.length;
}
console.log(isIsogram("Dermatoglyphics"));//, true
console.log(isIsogram("isogram")); //, true
console.log(isIsogram("moOse")); //, false
console.log(isIsogram("isIsogram")); //, false
console.log(isIsogram("")); //, true