javascript - 类型错误 : Cannot read property 'push' of undefined -Express

Question

我已经为使用 express 路由和创建服务器的 nodejs 应用程序编写了两个 Javascript 文件。由于我是初学者，我对此了解不多。当我运行该应用程序时，它向我显示以下错误:-

/usr/lib/node_modules/express/lib/router/index.js:472
    this.stack.push(layer);
              ^

TypeError: Cannot read property 'push' of undefined
    at Function.use (/usr/lib/node_modules/express/lib/router/index.js:472:15)
    at Object.<anonymous> (/home/dhiresh/Coding/angularjsapp/api.js:9:3)
    at Module._compile (module.js:570:32)
    at Object.Module._extensions..js (module.js:579:10)
    at Module.load (module.js:487:32)
    at tryModuleLoad (module.js:446:12)
    at Function.Module._load (module.js:438:3)
    at Module.require (module.js:497:17)
    at require (internal/module.js:20:19)
    at Object.<anonymous> (/home/dhiresh/Coding/angularjsapp/index.js:2:7)

index.js 文件如下:-

var express = require('express'),
api = require('./api'),
app=express(); 

app
.use(express.static('./public'))
.use('/api',api)
.get('*',function (req,res) {
    res.sendfile('public/index.html');
}).listen(3000);

api.js 文件如下:-

var express = require('express'),
 bourne = require('bourne'),
 bodyParser= require('body-parser'),

 db = new bourne('data.json'),

 router =express.Router(); 

 router
 .use(function(req,res,next){
    if(!req.user) req.user={ id:1 };
    next();
 })
 .use(bodyParser.json())
 .route('/contact')
 .get(function(req,res){
    db.find({userId : parseInt(req.user.id,10)},function(err,data){
        res.json(data);
    });
 })
 .post(function(req,res){
    var contact = req.body;
    contact.userId = req.user.id;

    db.insert(contact,function(err,data){
        res.json(data);
    });
 });

 router
 .param('id',function(req,res,next){
    req.dbQuery = { id:parseInt(req.params.id,10) }
 })
 .route('/contact/:id')
 .get(function(req,res){
    db.findOne(req.dbQuery,function(err,data){
        res.json(data);
    });
 })
 .put(function(req,res){
        var contact = req.body;
        delete contact.$promise;
        delete contact.$resolve;
        db.update(req.dbQuery,function(err,data){
        res.json(data[0]);
    })
    })
 .delete(function(req,res){
    db.delete(req.dbQuery,function(err,data){
        res.json(null);         
    })
 });

module.exports = router;

谁能告诉我这个问题的答案。

Answer 1

我的问题是缺少括号:

const router = require('express').Router;

将此更改为

const router = require('express').Router(); 

解决了我的问题。