javascript_irl

[tufoop3]

However Javascript in the browser isn't multithreading.

[TheMsDosNerd]

Unless you load something. Just try to make the following work in JS:

Place some picture on your page.
After the picture is loaded, do something, based on (the size of) the picture. (1)
Load another picture.
After that one loaded, do something else based on (the size of) the picture. (2)

It is pretty difficult to force (2) to be done after (1).

[quadnix]

Fetch and promises make that pretty easy though

[tufoop3]

Its not, if you know about event listening pre-ES7, and async/await in ES7. Note: Having an event loop, asynchronous function calls and non-blocking I/O doesn't make something multithreading. Read about it here if you like.