Node.js的 错误：模块不是函数

Question

i have a main file -- index.js:

var express = require('express');
var app = express();
var request = require('request');

var demo = require('demo');

// This app will only respond requests to the '/scrape' URL at port 3000.
app.get('/scrape', function (req, res) {
    var url = "http://www.l.com";

    request(url, function (error, response, html) { // two parameters: an URL and a callback
        if (!error) {
            demo(html);
        }
    });
});

var server = app.listen(3000, function () {
    var host = server.address().address;
    var port = server.address().port;

    console.log('Example app listening at http://%s:%s', host, port);
});

and my module is demo.js:

module.exports = function (html) {
    ....

    return JSON.stringify(json);
}

The error is :

TypeError: demo is not a function

I am new to node.js, i would like to know why this didn't work. Maybe i dont understand the real principle of module? Thank you for answer me first.

Answer 1

You're not exporting your module properly. It should be:

exports.demo = function ....

Answer 2

尝试在index.js中包含您的演示模块：
var demo = require('./demo.js');

Answer 3

For the other freshers who use module in node.js for the first time.

first, made a new module called the name of your module.js Second, it is not necessary to do " npm install demo --save ", if you want, it is also okay. Third, in the main js which u want to call this module, focus on the name and the path of the module, you should write var anyName = require('the name of your module'); , if they are in the same directory, you should write like this: var anyName = require('./the name of your module');