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

let str = 'aabbcdd';
let val = str.split('').reduce((a, e)=>{ if(str.indexOf(e) == str.lastIndexOf(e)) {a = e }; return a})
console.log(val); // c

Answer 2

Here is another approach:

Everytime you find equal chars store it in an array and break out of the loop. If the char is not found in the array then you have your first nonRepeating char

function nonRepeatingChars(value) {
  const memory = []
  for (let i = 0; i < value.length; i++) {
    for (let j = i + 1; j < value.length; j++) {
      if (value[i] === value[j]) {
        memory.push(value[j])
        break;
      }
    }
    if (!memory.some(x => x === value[i])) {
      return value[i];
    }
  }
  return "all chars have duplicates";
}

console.log('First non repeating char is:',nonRepeatingChars("esen"))
console.log('First non repeating char is:',nonRepeatingChars("esesn"))
console.log('First non repeating char is:',nonRepeatingChars("eseulsn"))
console.log('First non repeating char is:',nonRepeatingChars("esesnn"))