FAQ: Advanced Objects - Arrow Functions and this

This community-built FAQ covers the “Arrow Functions and this” exercise from the lesson “Advanced Objects”.

Paths and Courses
This exercise can be found in the following Codecademy content:

Web Development

Introduction To JavaScript

FAQs on the exercise Arrow Functions and this

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Why is the normal function declaration wrong in this example like:

const robot = {
  energyLevel: 100,
  function checkEnergy() {
    console.log(`Energy is currently at ${this.energyLevel}%.`)
  }
}

robot.checkEnergy();

because your defining a method, not a function.

Found a very useful article explaining this: https://www.freecodecamp.org/news/learn-es6-the-dope-way-part-ii-arrow-functions-and-the-this-keyword-381ac7a32881/

I didn’t find the example on Codecademy the easiest to understand.

The TL;DR is why ‘this’ in an arrow function won’t return the value is because of a JavaScript quick and ‘this’ when used inside the arrow function is now bound to the Global Object (where your global variables are) and NOT the object where the function is.

Hope this helps others who may have been a bit confused by this.