型別錯誤：無法讀取未定義的nodejs請求http的屬性“0”

我正在嘗試使用從 API 檢索 JSON 的不同命令擴展我的 Discord Bot。它適用于前幾個，如：

case 'results':
                request('http://ergast.com/api/f1/' args[2] '/' args[3] '/results.json', (error, response, body) => {
                    if(error) {msg.reply(error); }
                    const temp = JSON.parse(body);
                    let answer = '';
                    try {
                        for(var i = 0; i < temp.MRData.RaceTable.Races[0].Results.length; i  ) {
                            answer  = (i 1) '. ' 
                                  temp.MRData.RaceTable.Races[0].Results[i].Driver.givenName  ' '
                                  temp.MRData.RaceTable.Races[0].Results[i].Driver.familyName   ', ' 
                                  temp.MRData.RaceTable.Races[0].Results[i].Constructor.name   '\n';
                        }
                    }catch(error) {
                        console.log(error);
                        answer = 'Choose earlier race, no results in yet';
                    }   
                    msg.reply(answer);
                });
                break;

所以這很有效，很好。當我嘗試從另一個 API 呼叫（f1 賽季的驅動程式排名）獲取其他值時，我在 Heroku 部署的 Discordbot 上遇到了以下日志：

2021-10-22T13:35:57.470709 00:00 app[worker.1]: TypeError: Cannot read property '0' of undefined
    2021-10-22T13:35:57.470710 00:00 app[worker.1]:     at Request._callback (/app/index.js:254:73)
    2021-10-22T13:35:57.470710 00:00 app[worker.1]:     at Request.self.callback (/app/node_modules/request/request.js:185:22)
    2021-10-22T13:35:57.470710 00:00 app[worker.1]:     at Request.emit (events.js:400:28)
    2021-10-22T13:35:57.470711 00:00 app[worker.1]:     at Request.<anonymous> (/app/node_modules/request/request.js:1161:10)
    2021-10-22T13:35:57.470711 00:00 app[worker.1]:     at Request.emit (events.js:400:28)
    2021-10-22T13:35:57.470711 00:00 app[worker.1]:     at IncomingMessage.<anonymous> (/app/node_modules/request/request.js:1083:12)
        2021-10-22T13:35:57.470712 00:00 app[worker.1]:     at Object.onceWrapper (events.js:519:28)
        2021-10-22T13:35:57.470712 00:00 app[worker.1]:     at IncomingMessage.emit (events.js:412:35)
        2021-10-22T13:35:57.470712 00:00 app[worker.1]:     at endReadableNT 
(internal/streams/readable.js:1334:12)
        2021-10-22T13:35:57.470713 00:00 app[worker.1]:     at processTicksAndRejections 

(internal/process/task_queues.js:82:21)

我的錯誤代碼如下，日志說，Standingslist(?) 未定義，即使它可以在 http 回應中看到？錯誤代碼：

                case 'driverstandings':                 
                    request('http://ergast.com/api/f1/' args[2] '/driverStandings.json', (error, response, body) => {
                    if(error) {msg.reply(error); }
                    const temp = JSON.parse(body);
                    let answer = 'Season: '   temp.MRData.StandingsTable.StandingsList[0].round;
                    try {
                        for(var i = 0; i < temp.MRData.StandingsTable.StandingsList[0].DriverStandings.length; i  ) {
                            answer  = (i 1) '. ' 
                                  temp.MRData.StandingsTable.StandingsList[0].DriverStandings[i].Driver.givenName  ' '
                                  temp.MRData.StandingsTable.StandingsList[0].DriverStandings[i].Driver.familyName   ', ' 
                                  temp.MRData.StandingsTable.StandingsList[0].DriverStandings[i].points  ' points, wins: '
                                  temp.MRData.StandingsTable.StandingsList[0].DriverStandings[i].wins  '\n';
                        }
                    }catch(error) {
                        console.log(error);
                        answer = 'No entries';
                    }   
                    msg.reply(answer);
                });
                break;

語法方面，我就是想不通我的錯誤。

JSON 的結構如下：json 結構截圖

json 的 API 是：JSON

uj5u.com熱心網友回復：

我沒有試過你的代碼，看起來它應該是Standingslists而不是Standingslist。你可以試試嗎？

帕特里克

uj5u.com熱心網友回復：

錯字 -> StandingList 而不是StandingsList

標籤：节点.js json 不和谐.js 要求

上一篇：將元組作為鍵的字典轉換為JSON

下一篇：如何在c#中將href插入到json中