Join egghead, unlock knowledge.

Want more egghead?

This lesson is for members. Join us? Get access to all 3,000+ tutorials + a community with expert developers around the world.

Unlock This Lesson
Become a member
to unlock all features

Level Up!

Access all courses & lessons on egghead today and lock-in your price for life.


    How to use 'strict mode'


    Strict mode catches silent errors and throws them, fixes mistakes that can make it difficult for JavaScript engines to perform optimizations, and prohibits some syntax likely to be defined in future versions of ECMAScript. It can be used within entire scripts or to individual functions (does not apply to block statements). In this lesson we talk about some of these strict mode catches and see how to implement strict mode.