函数防抖，节流

        var fandou = true
        $(".begin").click(function () {
            if (fandou){
            fandou = false
                $.ajax({
                    type: "post",	//请求方式
                    url: "",
                    data: {

                    },
                    dataType: "json",
                    success: function (res) {
                        console.log(res)
						fandou = true
                    },
                });
            }
        })