var express = require('express')-无法读取未定义的属性'prototype' [英] var express = require('express') - Cannot read property 'prototype' of undefined

问题描述

我是Express的新手，如果这很简单，请原谅我.我有一个React项目，我正在尝试将Express添加到它.我添加了一个以以下行开头的.js文件来导入express:

I am new to Express, so forgive me if this is a simple one. I have a React project and I am trying to add Express to it. I have added a .js file that begins with the following line to import express:

var express = require('express');

但是，这会引发错误.

错误

request.js:31 Uncaught TypeError: Cannot read property 'prototype' of undefined
    at Object.<anonymous> (request.js:31)
    at __webpack_require__ (bootstrap 2c79a52…:555)
    at fn (bootstrap 2c79a52…:86)
    at Object.<anonymous> (express.js:20)
    at __webpack_require__ (bootstrap 2c79a52…:555)
    at fn (bootstrap 2c79a52…:86)
    at Object.<anonymous> (index.js:11)
    at __webpack_require__ (bootstrap 2c79a52…:555)
    at fn (bootstrap 2c79a52…:86)
    at Object.<anonymous> (myNewFile.js:1)

注意:myNewFile.js的第1行是var express = require('express');

Note: line 1 of myNewFile.js is var express = require('express');

我确实尝试过npm install express，所以我应该可以访问express并且它应该是最新的，但是看来我仍然会收到此错误.

I did try npm install express so I should have access to express and it should be up to date, but it seems that I still get this error.

如何解决此错误以及为什么发生?

谢谢.

推荐答案

您需要在webpack配置中指定target:

You need to specify target in webpack config:

target: 'node'

这仅在服务器端作为node.js程序起作用.

And this will work only on server side as node.js program.

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