判断⼀个字符串中出现次数最多的字符，统计这个次数

// 找出⼀个字符串中出现次数最多的字符，并统计出现的次数 // "ababajshbaasdaaaa" => {char:'a',count:9}  

 var str = "ababajshbaasdaaaa"

    function computeString(str) {
      let obj = {}, res = { char: '', count: 0 }
      for (let i = 0, len = str.length; i < len; i++) {
        const item = str[i]
        obj[item] = obj[item] ? obj[item] + 1 : 1
        if (obj[item] > res.count) {
          res.char = item
          res.count = obj[item]
        }
      }
      return res
    }

    let val = computeString(str)
    console.log(val); // {char: 'a', count: 9}