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.


    Use JavaScript's for-in Loop on Objects with Prototypes


    Loops can behave differently when objects have chained prototype objects. Let's see the difference we get when we use the for-in loop on an object without a prototype, as opposed to an object with a prototype object.