return the first non repeating character in a string in javascript

Question

So I tried looking for this in the search but the closest I could come is a similar answer in several different languages, I would like to use Javascript to do it.

T

Answer 1

Here's a Solution using Regex to replace all repeating characters and then returning the first character.

function firstNonRepeat(str) {

   // Sorting str so that all repeating characters will come together & replacing it with empty string and taking first character using substr.

   var rsl = str.split('').sort().join('').replace(/(\w)\1+/g,'').substr(0,1);

   if(rsl) return rsl;

   else return 'All characters are repeated in ' + str;

}

console.log(firstNonRepeat('aaabcccdeeef'));
console.log(firstNonRepeat('aaacbdcee'));
console.log(firstNonRepeat('aabcbd'));