Javascript

Javascript is scripting language, made for web. It needs javascript runtime to execute javascript code.

At the begin, there is only browser take responsible javascript runtime to execute javascript code from html page with tags <script> (Client side). Recently Javascript can run in every machine with NodeJS - a javascript runtime (Server side).

Javascript becomes ECMA script standard from 1999. It grows up with several version, the current version is ECMA script 6 but only ECMA script 5 is supported by all current browsers, ECMA6 is not supported by all current browsers.

Now a day, we can use javascript and ecma script equally.

Usage

• Handle event : user input, DOM element changes, data received from server,..
• Manipulate DOM elements.
• Generate DOM elements.
• To write web service by using NodeJS or other js runtime can run on local machine.

Dark side

• Javascript is very complicated with "this" pointer.
• It's support OOP but there is no term of "class" , so constructing large application is very hard : reusable, maintenance,...
• Interacts with DOM elements is quite messy.

Evolution

To make javascript is more comportable, easy to build large application, take advantage of OOP, some organization makes higher abstract language base on javascript to avoid javascript's badness.

These languages you might know: ECMA script 6, Reactjs, Angularjs, Typescript, Coffeescript,...

All of these have common features:

• Compile to javascript
• Strongly supports OOP
• Easy manipulates DOM elements