js 分组数组

思路：

1、先将数组按照一定规则排序；

2、再拆分数组到Map中，按Key分类；

3、再从Map中遍历取出要显示的内容；

sortBroadList: function (broadcastList) {
            var broadList = broadcastList.sort(function (d1, d2) {
                var d1ChatAt = (d1.first_pinyin ? d1.first_pinyin.toString().charCodeAt(0) : 91);
                var d2ChatAt = (d2.first_pinyin ? d2.first_pinyin.toString().charCodeAt(0) : 91);
                return d2ChatAt - d1ChatAt;
            }).reverse();

            var result = new Map();
            for (var item of broadList) {
                var pinyin = item.first_pinyin ? item.first_pinyin : '#';
                if (result.get(pinyin)) {
                    result.get(pinyin).values.push(item);
                } else {
                    result.set(pinyin, {key: pinyin, values: [item]});
                }
            }

            uc.util.LogUtil.info('ContactManager', 'sortBroadList', 'sort broadcastlist result:', {
                broadList: broadList
            });
            return result;
        },

        loadBroadcastItem: function (broadcastList) {
            var parentPanel = _this.getLatestClickedContactsPanel();
            var ul = parentPanel.find('.broadcast-parent');
            ul.empty();
            var broadList = _this.sortBroadList(broadcastList);
            broadList.forEach(function (item) {
                var hasAlphabetical = ul.find(`li[alphabetical-key="${item.key}"]`);
                if (!hasAlphabetical.length) {
                    ul.append(_this.getAlphabetical(item.key));
                }
                for (var broadcast of item.values) {
                    ul.append(_this.getBroadcastTpl(broadcast));
                    _this.broadcastCache.addContact(broadcast.board_id, broadcast);
                }
            });
        },

结果：