var bb;
        $.ajax({

            type: 'get',
            url: '/store/attachment/getAllGroup',
            success:function(result) {

                console.log(result)
                for(var i=0;i'+result[i].name+''+result[i].count+'')

                    console.log($(".style_left").attr('a'))
                }
                $('.style_left').each(function(){

                    $(this).click(function(){
//                        console.log("555"+$(this));
                        console.log($(this).attr('a'))
                        bb = $(this).attr('a')
                        $('.style_left').css('background-color',"#f2f2f2")
                        $(this).css("background-color","#ffffff")
                        return bb;
                    })

                })
                show_group_img(0)
            }
        });
        console.log(bb)  //undefind
        此时的bb无法获取，是undefind