Usage

Usage

Embedded

<script>
  // Logic
</script>

External

<script src="path/to/global.js"></script>
<script src="path/to/section.js"></script>

Statements

• end in semicolon
• whitespaces ignored
• can put multiple statments on a single line
• statements can span lines

Execution Context

Memory Allocation Phase

: Functs and vars get stored into mem as key-val pairs

Code Execution Phase

: Thread of execution, whereby vals of functs and vars are updated in order

When a function is called, a new Execution Context is created inside the calling execution context.

Parsing Order

• HTML file is parsed until it hits <script> tag
• Parsing is paused until script is fetched and executed.
• JS files are executed in order of appearance in the doc.

async Attrib

<script src="script.js" async>

• js file is downloaded at same time as HTML parsing.
• When file is finished downloading, HTML parsing is paused until code is executed.

defer Attrib

<script src="script.js" defer>

• file is download during HTML parsing
• file executes post parsing
• deferred scripts execute in order of appearance