Question 1

What will happen to DOM tree if some issue happens in script tag?

Accepted Answer

The browser reads the html file from top to bottom, creating the DOM Tree and when it sees a <script> , it stops to download and execute it until the parse goes through the whole page.

Question 2

How is JavaScript parsed in the browser?

Accepted Answer

JavaScript CompilationThe scripts are parsed into abstract syntax trees. Some browser engines take the Abstract Syntax Tree and pass it into an interpreter, outputting bytecode which is executed on the main thread. This is known as JavaScript compilation.

Question 3

How does a browser handle JavaScript and HTML?

Accepted Answer

The script sections of a web page are handled by the browser's JavaScript interpreter, which may be an intrinsic part of the browser but usually is a distinct module, sometimes even a completely distinct project (Chrome uses V8; IE uses JScript; Firefox uses SpiderMonkey; etc.).