node.js包括类文件

Question

I got 2 files:

start.js

    var ConversationModule = require('./src/classes/conversation/Conversation.js');
    ConversationModule.sayhello();

conversation.js

    var ConversationModule = new Object();

    ConversationModule.sayhello = function () {
    console.log("hello");
    };

    exports.ConversationModule = ConversationModule();

In start.js I cannot call the sayhello() method. I get following error

TypeError: object is not a function

I just don't get it why it doesn't work - I'm new to node :)

Answer 1

You are trying to export ConversationModule as a function, which it is not. Use this instead:

exports.ConversationModule = ConversationModule;

Since you're also assigning the variable as a property of exports , you'd have to call it like this:

var ConversationModule = require('./file').ConversationModule;
ConversationModule.sayhello();

If you don't want to do that, assign the object to module.exports :

module.exports = ConversationModule;

And call it like this:

var ConversationModule = require('./file');
ConversationModule.sayhello();

Answer 2

Given that you've named the file conversation.js, you probably intend to define solely the "conversation module" in that particular file. (One file per logical module is a good practice) In that case, it would be cleaner to change your export code, and leave your require code as you had it originally.

start.js

var ConversationModule = require('./src/classes/conversation/Conversation.js');
    ConversationModule.sayhello();

conversation.js

   var ConversationModule = new Object();

   ConversationModule.sayhello = function () {
     console.log("hello");
   };

   module.exports = ConversationModule;

Assigning something to module.exports makes this value available when you require the module with require .

Answer 3

conversation.js:

var conversationModule = new Object();

conversationModule.sayhello = function () {
console.log("hello");
};

exports.conversationModule = conversationModule;

start.js:

var conversationModule =  require('./src/classes/conversation/Conversation.js').conversationModule;
conversationModule.sayhello();