var leftMostRepeatingCharacter = function (s) {
  let map = {};
  for (let i = 0; i < s.length; i++) {
    map[s[i]] = (map[s[i]] || 0) + 1;
  }
  if (Object.keys(map).length > 0) {
    for (let val in map) {
      console.log(val);
      if (map[val] > 1) {
        console.log(val);
        return val;
      }
    }
  }
};

console.log(leftMostRepeatingCharacter("ahbhagdc"));