JS得到字符串中重复次数最多的项两种方法

<script>
 var str = '85skkkhj22gdg541232286oe458546445sada2fasa51233148dskf7212772';
 var res = countSort(str); //归总为对象素组
 rr = sortArrayByItem(res, 'len'); //根据每一项的length属性排序
 var maxCount = rr[0];
 console.log('重复最多的项是:' + maxCount.item + "---重复的次数是：" + maxCount.len);
 //字符串重复项的归总（以对象数组的形式）
 function countSort(str) {
 var array = str.split('');
 var filter = [];
 var result = [];
 //查找与tar相同的所有项,返回最终一位数组集合arr
 var get = function (str, tar, arr, tmp) {
 if (str.indexOf(tar) >= 0) {
 var tmp = str.slice(str.indexOf(tar) + 1);
 arr.push(tar);
 get(tmp, tar, arr, tmp);
 }
 return arr;
 }
 for (i in array) {
 var elm = [];
 var tmp;
 var fstr = filter.join(); //已完成归并的所用项
 if (fstr.indexOf(array[i]) >= 0)
 continue;
 else {
 var tmp_arr = get(str, array[i], elm, tmp); //完成的一项归总
 result.push({
 item: tmp_arr[0]
 , len: tmp_arr.length
 });
 filter.push(array[i]);
 }
 }
 return result;
 }
 //对象数组的排序，item代表要根据那个属性来做排序(从大到小)
 function sortArrayByItem(array, item) {
 for (var i = 0; i < array.length - 1; i++) {
 for (var j = i + 1; j < array.length; j++) {
 if (array[i][item] < array[j][item]) {
 var tmp = array[i];
 array[i] = array[j];
 array[j] = tmp;
 }
 }
 }
 return array;
 }
</script>

<script>
　var tt = Char('dj84dccvdda85454kk444gghg6675786fh');
 console.log(tt)
 tt = maxC(tt);
 console.log(tt)
 function Char(str) {
 var uchars = {};
 str.replace(/\S/g, function (l) {
 uchars[l] = (isNaN(uchars[l])) ? 1 : uchars[l] + 1
 })
 return uchars
 }
 function maxC(obj) {
 var maxCount = 0;
 var maxItem = null;
 for (var i in obj) {
 if (obj[i] > maxCount) {
 maxCount = obj[i];
 maxItem = i;
 }
 }
 return {
 maxCount: maxCount
 , maxItem: maxItem
 };
 }
</script>