0_what_is_javascript

dz / mdn / js / 0_javascript_first_steps / 0_what_is_javascript

Summary

What is Javascript?

Node Tree

• javascript
  • tag_script
    • uses_script_tag
      • external
      • internal
        • external
    • defer
      • HTML_body_parsed
      • async
        • download_noblock
          • blocks_page
            • no_guarantee_order
        • load_background_ASAP
  • uses_script_tag
    • external
    • internal
      • external
  • API
    • third_party_API
      • twitter
      • google_maps
      • grab_code_info_somewhere
    • browser_API
      • AV_APIs
      • DOM_API
      • canvas_webgl
      • geolocation
    • ready_made_set_code_building_blocks
  • QuerySelectorAll
  • addEventListener
    • DOMContentLoaded
      • HTML_body_parsed
    • QuerySelectorAll
  • builds_on_html_css
  • client_side
    • run_on_users_computer
    • server_side
      • server_side_languages
  • comments
    • single_line
  • dynamic
    • static_code
    • ability_to_update_page
  • event_listener
    • addEventListener
      • DOMContentLoaded
        • HTML_body_parsed
      • QuerySelectorAll
  • exec_environment
    • bucket_for_running_code
    • code_run_separately
  • implement_complex_features_on_web
    • complex_feature_ex
  • inline_js_handlers
  • interpretted
    • compiled
    • just_in_time_compiling
  • multiline

Nodes

javascript
content	JavaScript
children	tag_script, uses_script_tag, API, QuerySelectorAll, addEventListener, builds_on_html_css, client_side, comments, dynamic, event_listener, exec_environment, implement_complex_features_on_web, inline_js_handlers, interpretted, multiline

implement_complex_features_on_web
content	Scripting/programming language that allows you to implement complex features on web pages
children	complex_feature_ex (examples of "complex features")
parents	javascript

complex_feature_ex
content	Create dynamically udpating content, control multimedia, animate images
parents	implement_complex_features_on_web

builds_on_html_css
content	Buils on top of HTML, CSS
parents	javascript

API
content	Application Programming Interface (API)
children	third_party_API, browser_API, ready_made_set_code_building_blocks (description)
parents	javascript

ready_made_set_code_building_blocks
content	ready-made set of code building blocks that allow a dev to implement programs otherwise hard or impossible
parents	API

browser_API
content	Browser APIs
children	AV_APIs, DOM_API, canvas_webgl, geolocation
parents	API

DOM_API
content	DOM API
parents	browser_API

geolocation
content	Geolocation
parents	browser_API

canvas_webgl
content	Canvas / WebGL
parents	browser_API

AV_APIs
content	AV APIs HTMLMediaElement and WebRTC
parents	browser_API

third_party_API
content	Third-Party APIs
children	twitter, google_maps, grab_code_info_somewhere
parents	API

twitter
content	twitter
parents	third_party_API

google_maps
content	Google Maps
parents	third_party_API

grab_code_info_somewhere
content	Generally have to grab code and info somewhere on the web.
parents	third_party_API

exec_environment
content	Execution environment
children	bucket_for_running_code, code_run_separately
parents	javascript

bucket_for_running_code
content	Each browser tab has its own bucket for running code in
parents	exec_environment

code_run_separately
content	Code is run separately
parents	exec_environment

interpretted
content	Interpretted
children	compiled (versus), just_in_time_compiling
parents	javascript

compiled
content	Compiled
parents	interpretted

just_in_time_compiling
content	Most modern JS interpreters use a technique called just-in-time compiling to improve performance
parents	interpretted

client_side
content	Client-side
children	run_on_users_computer, server_side (versus)
parents	javascript

server_side
content	Server-sisde
children	server_side_languages
parents	client_side

run_on_users_computer
content	Run on Users Computer
parents	client_side

server_side_languages
content	PHP, Python, Ruby, ASP.NET, Javascript (via node.js)
parents	server_side

dynamic
content	Dynamic
children	static_code (versus), ability_to_update_page (description)
parents	javascript

static_code
content	Static code
parents	dynamic

ability_to_update_page
content	Ability to udpate display of web page / app to show different things in different circumstances
parents	dynamic

uses_script_tag
content	Uses <script>
children	external, internal
parents	javascript, tag_script

internal
content	internal
children	external (versus)
parents	uses_script_tag

external
content	external
parents	uses_script_tag, internal

inline_js_handlers
content	Inline JS handlers
parents	javascript
remarks	bad practice to use these

QuerySelectorAll
content	QuerySelectorAll()
parents	javascript, addEventListener

addEventListener
content	addEventListener()
children	DOMContentLoaded, QuerySelectorAll
parents	javascript, event_listener

event_listener
content	Event Listener
children	addEventListener
parents	javascript

DOMContentLoaded
content	DOMContentLoaded
children	HTML_body_parsed
parents	addEventListener

tag_script
content	<script>
children	uses_script_tag, defer
parents	javascript

defer
content	defer
children	HTML_body_parsed (modern approach), async
parents	tag_script

HTML_body_parsed
content	Signifies HTML body is parsed
parents	DOMContentLoaded, defer

async
content	async vs
children	download_noblock, load_background_ASAP (when to use)
parents	defer

load_background_ASAP
content	Should be used to load in place background scripts as soon as possible
parents	async

no_guarantee_order
content	no guarantee on execution order
parents	blocks_page

blocks_page
content	Blocks page when executing
children	no_guarantee_order
parents	download_noblock

download_noblock
content	Downloads without blocking
children	blocks_page
parents	async

comments
content	comments
children	single_line
parents	javascript

single_line
content	Single Line (//)
parents	comments

multiline
content	multiline (/* */)
parents	javascript