ECMAScript 5 introduced strict mode to JavaScript. The intent is to allow developers to opt-in to a “better” version of JavaScript, where some of the most common and egregious errors are handled differently. For a while, I was skeptical, especially with only one browser (Firefox) initially supporting strict mode. Fast forward to today, every major browser supports strict mode in their latest version, including Internet Explorer 10 and Opera 12. It’s time to start using strict mode.