jquery ajax 报错 Cannot convert undefined or null to object at entries (<anonymous>)

这个错误是因为你有用到未定义的对象

比如我的代码:

$("#delete").click(function(){
            layer.confirm('确定删除此接口?', {
                btn: ['确定','取消'] //按钮
                }, function(){
                    layer.closeAll();
                    $.ajax({
                        url: domain+"/processDetail/delete",
                        method: "POST",
                        data:{"processId":processId,"seqNo":lastSeqNo},
                        contentType: "application/x-www-form-urlencoded",
                        dataType: "json",
                        beforeSend: function (XMLHttpRequest) {
                            var token = myLocalStorage.getItem("sm-token");
                            checkToken(token);
                            XMLHttpRequest.setRequestHeader("sm-token", token);
                            layer.load();
                        },
                        complete: function () {
                            layer.closeAll("loading");
                        },
                        success: function(data) {
                            if(data.code == 200){
                                window.location.href="mainProcessUpdate.html?processId="+processId;
                            }else{
                                layerAlert(data.message);
                            }
                        },
                        error:function(jqXHR){
                            layerAlertDefault();
                        }
                    });
                }, function(){
            });
        })

我的错误就是因为lastSeqNo忘记定义了

所以好好检查你使用到的对象是否有未定义的