javascript - NodeJS this.var 未定义

Question

index.js

const request = require('request');

class ScheduleDownloader {

ScheduleDownloader(schoolId, username, schoolPassword) {
    this.schoolId = schoolId;
    this.username = username;
    this.schoolPassword = schoolPassword;
}

getScheduleAtDate(dateString) {
    console.log(`https://${this.username}:${this.schoolPassword}@www.myurl.de/${this.schoolId}/vplan/vdaten/VplanKl${dateString}.xml`)
    /*request({url: `https://${this.username}:${this.schoolPassword}@www.myurl.de/${this.schoolId}/vplan/vdaten/VplanKl${dateString}.xml`}, (err, res, body) => {
        if(err) console.error(err);
        console.log(body);
    });*/    // COMMENTED OUT FOR TESTING
};

module.exports = ScheduleDownloader;


var s = new ScheduleDownloader(10192417, 'schueler', 'S53998t');
s.getScheduleAtDate(20200317); // For testing in this class

输出

https://undefined:undefined@mnyurl.de/undefined/vplan/vdaten/VplanKl20200317.xml // undefined
https://www.myurl.de/10192417/vplan/vdaten/VplanKl20200317.xml // What it should be

如您所见，我正在尝试请求 xml 文件。我发现this.username等都是未定义的。我该如何解决？这又是什么原因呢？ (抱歉，我是 JavaScript 新手)

Answer 1

在 javascript 构造函数中，称为构造函数，而不是类名，因此永远不会调用您的函数 ScheduleDownloader。将其更改为构造函数:一些阅读: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes