1const getMaxLetter = (str) => {
2  let max = 0;
3  let maxChar = '';
4  str.split('').forEach((char) => {
5    if (str.split(char).length > max) {
6      max = str.split(char).length - 1;
7      maxChar = char;
8    }
9  });
10  return `The max letter is : ${maxChar} and the max number of times it is seen is: ${max} times`;
11};

1function maxChar(str) {
2  let charCountObj = {};
3  let maxChar = "";
4  let maxCount = 0;
5
6  //  Fill out CharCountObj
7  //  Updates new MaxCount
8
9  for (let i = 0; i < str.length; i++) {
10    const char = str[i];
11
12    charCountObj[char] = charCountObj[char] + 1 || 1;
13
14    if (charCountObj[char] > maxCount) {
15      maxChar = char;
16      maxCount = charCountObj[char];
17    }
18  }
19
20  return maxChar;
21}
22