Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

JavaScript Object-Oriented JavaScript Object Basics Dot Notation & Bracket Notation

What is " this " in javascript?

const teacher = {

firstName : "Ashley",

lastName : "Boucher",

printName: function(){

  console.log(this.firstName + this.lastName);

} }

I do not get what " this " does. I cant check console because work space have port which is weird. For the case, is the " this " getting " Ashley " ?

1 Answer

Alexander Besse
seal-mask
.a{fill-rule:evenodd;}techdegree seal-36
Alexander Besse
Full Stack JavaScript Techdegree Graduate 35,115 Points

Hi Peter Huang,

From W3Schools:

In JavaScript, the this keyword refers to an object.

Which object depends on how this is being invoked (used or called).

The this keyword refers to different objects depending on how it is used:

In an object method, this refers to the object.
Alone, this refers to the global object.
In a function, this refers to the global object.
In a function, in strict mode, this is undefined.
In an event, this refers to the element that received the event.
Methods like call(), apply(), and bind() can refer this to any object.

Source