Why does require('underscore') return undefined when executed at the node.js REPL?

Question

When I run node in my console and type var _ = require(\'underscore\');, _ ends up undefined. If I put the same code in a file and execute it, the

Answer 1

The Node repl binds _ to the value of the last evaluated input; which overwrites your _ binding in var _ = ...;. Also see the node.js documentation on the repl.

This is true no matter what replaces ..., for example:

$ node
> var _ = "any value";
undefined
> _
undefined