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 trialDaniel Benisti
Front End Web Development Techdegree Graduate 22,224 PointsHow the method of the class beings passed aound?
Hi, The method within the class not in the constructor, So how it is passed around?
Thanks!
2 Answers
Daoud Merchant
5,135 PointsWith respect to previous commenters, I think it's important to understand (as Ms. Boucher says) that class
is just syntactic sugar for prototypes.
Any object can access a property/method on one of its prototypes. Consider the following:
const greeting = "Hello";
greeting.toLowerCase(); // "hello"
It looks like the method toLowerCase
is being accessed on greeting
itself, but greeting
is just a string... In fact, it is a method of the prototype of the global String
object (hence MDN's docs reference to 'String.prototype.toLowerCase'), but greeting
can access it because a string automatically shares the same prototype as the String
object.
This is all that class
does in JS: when you 'instantiate' a class, you create an object and tell it to share the same prototype as the 'class' object, which contains the methods. Therefore you can call them on the 'instantiations' through prototypical inheritance. It is not 'passed around', it is 'borrowed' or 'accessed' from a prototype.
I hope this helps!
Steven Parker
231,184 PointsMethods are peers of the constructor, they don't go inside it. But they are still part of the class, so they will exist in any instance of that class.
Daniel Benisti
Front End Web Development Techdegree Graduate 22,224 Pointsif i'm going to put properties outside of the constructors they also would be exist in any instance?
Steven Parker
231,184 PointsBoth methods and properties are defined inside the class, but outside of the constructor. Think of the constructor as just another method (but one with a special purpose).