AlgoDaily 14: Find First Non-Repeating Character

https://algodaily.com/challenges/find-first-non-repeating-character

This shouldn’t be too hard with a hash map of characters to counts, relying on JavaScript objects having ordered keys to then find the first character with a single occurrence.

function firstNonRepeat(str) {
        const counts = {}
        for (let char of str) {
                counts[char] = counts[char] ? counts[char] + 1 : 1;
        }
        for (let char in counts) {
                if (counts[char] === 1) {
                        return char;
                }
        }
        return "";
}

Tech mentioned