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 Asynchronous Programming with JavaScript Understanding Promises Promises Review

The Global var "value" is passed and modified (!) by the functions call. But it's declared as a const !

How it's possible ?

3 Answers

Steven Parker
Steven Parker
231,268 Points

The original "value" is not modified, but a new value is computed using it which is then return‍ed. The new value eventually gets passed down to "finalValue" where it is logged, but it is never stored back into "value".

MSM KSD14
MSM KSD14
270 Points

This is very very interesting. So does that mean the resolve method have a closure in the global variable environment?

Steven Parker
Steven Parker
231,268 Points

This is an example of simple argument passing and is not related to closures.

MSM KSD14
MSM KSD14
270 Points

Oh i see, let me rewatch it again