Js--ecmascript

# # ECMAScript
-It is a scripting language specification developed and published by the ECMA Organization (formerly the European Association of Computer Manufacturers)
-JavaScript is the implementation of the ECMA
-ECMAScript and JavaScript usually express the same meaning

# # # JS consists of three parts:
-ECMAScript (CORE)
-Extended ==> Browser side
* BOM (Browser object model)
* DOM (Document Object model)
-Extended ==> Server side
* Node


# # # Several important versions of ES
-es5:09 Year Release
-ES6 (ES2015): Published in 15, also known as ECMA2015
-ES7 (ES2016): Released in 16, also known as ECMA2016 (little change)


# # # Write location
1. Write to the tag in the specified attribute.
-The coupling of structure and behavior is caused
-Inconvenient post-maintenance is not recommended
2. Create a JS code area using the ' <script> ' tab
-"' <script type=" Text/javascript "></script>"
3. Write in an external JS file. "<script>" tag Introduction
-"' <script type=" Text/javascript "src=" Js/new_file.js "></script>"

# # # Notes
-Multiline comments (not nested)/**/
-Single comment//

# # # JS Output
-Browser Bullet Box
-"Alert (" ")"
-Console output Content
-"' Console.log ()"
-control Browser page output content
-"' document.write ()"
-Turn on timer
-"' Console.time ()"
-Stop Timer
-"' Console.timeend ()"

Js--ecmascript