It's not really a fault of node so much as a fault of JavaScript. While JavaScript is a beautiful and expressive language, it does have some annoying pitfalls;

It's not really a fault of node so much as a fault of JavaScript. While JavaScript is a beautiful and expressive language, it does have some annoying pitfalls; this is just one of them. Happily, this is all changing--in the long run, future versions of JavaScript should polish away these issues while maintaining the fundamentally sound core of the language. In the short run "use strict" lets you realize some of the upcoming improvements in otherwise legacy code.