本质是获得数据，然后添加到页面中，并加入样式

        $("#table").on("mouseover", "tr", function () {
            var data = this.getAttribute(‘data-points‘);
            if (!data) return;
            data = JSON.parse(data);

            var ht = ‘‘;
            var i = 0;

            var parse = function (data) {
                if (data.children.length) {//如果data.children.length有长度
                    ht += ‘<h4 class="k_point">‘ + "知识点" + ‘</h4>‘;
                    ht += ‘<h4 class="k_point">‘ + data.title + "" + ‘</h4>‘;
                    for (var j = 0; j < data.children.length; j++) {
                        parse(data.children[j]);

                    }
                } else if (data.checked == true) {
                    ht += ‘<p class="s_point">‘ + data.title + (‘‘, ‘<span class="greenword">已掌握</span>‘);
                } else {
                    ht += ‘<p class="s_point">‘ + data.title + (‘‘, ‘<span class="redword">未掌握</span>‘);
                }


            };

            for (var i = 0; i < data.length; i++) {
                parse(data[i]);
            }

            $("#points").html(ht);
        });