first-unique-character-in-a-string_0520.html

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>first-unique-character-in-a-string</title>
  </head>
  <body></body>
  <script>
    /**
     * @param {string} s
     * @return {number}
     */
    var firstUniqChar = function (s) {
      let res = -1;
      let arr = s.split("");
      const map = new Map();

      arr.forEach((str, i) => {
        map.set(str, map.get(str) + 1 || 1);
      });

      for (let [key, value] of map) {
        if (value == 1) {
          res = arr.indexOf(key);
          break;
        }
      }

      return res;
    };
  </script>
</html>