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

The most satisfactory and easy to understand answer is the following.

function firstNotRepeatingCharacter(s) {
        
    const arr = s.split("");

    for(let i = 0; i < arr.length; i++){
        let chr = arr[i];
        if( arr.indexOf(arr[i]) == arr.lastIndexOf(arr[i])){
            return arr[i]
        }            
    }
    
    return "_"
}

Explanation: It loops through all the characters of a string from forward and backward and then compares the values. If the index of both forward and backward search is true then it returns that character.