REPL中的Require（）似乎无法正常工作

Question

Problem: I just started out in node.js and when using REPL to require a module, its function keeps showing undefined. Where did it go wrong?

Also, why does the var s = require('./simple'); line result in an undefined response? I am using node v0.6.2

simple.js

var counts = 0;
exports.next = function() { counts++; }

What I did in REPL

> var s = require('./simple');
undefined
> s.next
[Function]
> s.next()
undefined
> s.next();
undefined

Answer 1

That is completely normal, since your function doesn't actually return anything it would return undefined by default. Try this exports.next = function() {return counts++; } exports.next = function() {return counts++; } you get the number before the addition.