1. // 判断一个字符串中出现次数最多的字符，统计这个次数
    3. function countCharNum(str) {
    4.   let obj = {}
    5.   for (let i = 0; i < str.length; i++) {
    6.     let temp = str[i]
    7.     if (obj.hasOwnProperty(temp)) {
    8.       obj[temp]++;
    9.     } else {
    10.       obj[temp] = 1;
    11.     }
    12.   }
    13.   let char = '';
    14.   let max = 0;
    15.   for (let key in obj) {
    16.     if (max < obj[key]) {
    17.       max = obj[key];
    18.       char = key;
    19.     }
    20.   }
    21.   return char;
    22. }
    24. console.log(countCharNum('aghdfjhjjjkAAhghje'));