Using the Underscore module with Node.js

Question

I've been learning about node.js and modules, and can't seem to get the Underscore library to work properly... it seems that the first time I use a function from Underscore, it overwrites the _ object with the result of my function call. Anyone know what's going on? For example, here is a session from the node.js REPL:

Admin-MacBook-Pro:test admin$ node
> require("./underscore-min")
{ [Function]
  _: [Circular],
  VERSION: '1.1.4',
  forEach: [Function],
  each: [Function],
  map: [Function],
  inject: [Function],
  (...more functions...)
  templateSettings: { evaluate: /<%([sS]+?)%>/g, interpolate: /<%=([sS]+?)%>/g },
  template: [Function] }
> _.max([1,2,3])
3
> _.max([4,5,6])
TypeError: Object 3 has no method 'max'
    at [object Context]:1:3
    at Interface.<anonymous> (repl.js:171:22)
    at Interface.emit (events.js:64:17)
    at Interface._onLine (readline.js:153:10)
    at Interface._line (readline.js:408:8)
    at Interface._ttyWrite (readline.js:585:14)
    at ReadStream.<anonymous> (readline.js:73:12)
    at ReadStream.emit (events.js:81:20)
    at ReadStream._emitKey (tty_posix.js:307:10)
    at ReadStream.onData (tty_posix.js:70:12)
> _
3

When I make Javascript files myself and import them, they seem to be working properly. Maybe there's something special with the Underscore library?

Answer 1

As of today (April 30, 2012) you can use Underscore as usual on your Node.js code. Previous comments are right pointing that REPL interface (Node's command line mode) uses the "_" to hold the last result BUT on you are free to use it on your code files and it will work without a problem by doing the standard:

var _ = require('underscore');

Happy coding!