HTML parse order / script execution order

Question

the following lines are from the official jQuery website

Answer 1

Lets talk about the more traditional way of handling without using attribute defer or async

The browsers will:

1. Download scripts, blocking other resource from downloading

2. Parse the scripts

3. Execute the scripts

See Ch1, Loading and Executing from High Performance JavaScript

Here's another good reference 12.3. Execution of JavaScript Programs from JavaScript: The Definitive Guide, 4th Edition

Answer 2

Yes it will wait with parsing any html until the script is loaded and parsed. This is one reason why you should load externa scripts at the end of your page so script will not blocking the html rendering.

Answer 3

The scripts are executed in the order they are in the document. The browser waits for the script to load before executing the scripts following it.

If this weren't the case, you couldn't have any two files be dependent of each other. You'd have to put everything in the same file because otherwise the script execution order would be practically random.