1. 🧐 Expected Output

--- Examples
maxChar("abcccccccd") === "c"
maxChar("apple 1231111") === "1"

2. 🤔 My Solution

function maxChar(str) {
  const updatedStr = str.split("").filter(element => element !== '')
  const result = {}

  for (let index = 0; index < updatedStr.length; index++) {
    const element = updatedStr[index]
    if (element in result) {
      result[element] ++
    } else {
      result[element] = 1
    }
  }

  const resultKeys = Object.keys(result)
  const resultValues = Object.values(result)
  const max = Math.max(...resultValues)

  resultKeys.forEach((val) =>{
    if (result[val] === max) {
      return val
    }
  })
}

3. 🎊 Best Solution

function maxChar(str) {
  const result = {}
  let max = 0
  let maxChar = ''

  for (const char of str) {
    if (char in result) {
      result[char] ++
    } else {
      result[char] = 1
    } 
  }

  for (let char in result) {
    if (result[char] > max) {
      max = result[char]
      maxChar = char
    }
  }
  return maxChar
}