统计字符串中字母个数并且统计最多字母数

var str = "aaaabbbccccddfgh";
        function dealStr(str) {
            var obj = {};
            for (var i = 0; i < str.length; i++) {
                var v = str.charAt(i);
                // console.log(v)
                if (obj[v] && obj[v].value === v) {
                    ++obj[v].count
                } else {
                    obj[v] = {
                        count: 1,
                        value: v 
                    }
                } 
            }
            return obj;
        }
        var obj = dealStr(str);
        for (key in obj) {
            console.log(obj[key].value + '=' + obj[key].count)
        }