// Find first non-repeating character in a string function findUnique(str) { if (!str) return false; var unique; for (var i = 0; i < str.length; i++) { unique = true; for (var j = 0; j < str.length; j++) { if (str[i].toLowerCase() == str[j].toLowerCase() && i != j) unique = false; } if (unique) return str[i]; } return false; } console.log( findUnique("racecar") )