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 is one other solution just using array, using 26 unique character as length of array:

var firstUniqChar = (function(s) {
    var arr = [];
    var str = s.toLowerCase();
    for(let c of str){
      let index = c.charCodeAt(0) - "a".charCodeAt(0);
      arr[index]? ++arr[index]: arr[index]=1;
    }
    
    for(let c of str){
      let index = c.charCodeAt(0) - 97;
      if(arr[index] == 1){
        return c;
      };
    }

    return -1;
}("aabcbd"));

console.log(firstUniqChar);