(public).sospep.subjects ~ view article ~ 001-javascript-overview

<h1 style="text-align: center; padding-left: 30px;">javascript</h1>
<h2>[WHAT]</h2>
<ol>
<li><strong>] JavaScript(js) is a dynamically typed, multi paradigm, interpreted programming language</strong> - that features ( dynamic objects, loose typing, lambda's, c like syntax , regex) and can be used to write&nbsp; object oriented, functional and imperative(structural) programs.</li>
</ol>
<h2>[history bit]</h2>
<ol>
<li>] javascript originated in the web browser as&nbsp;a 'scripting&nbsp;language' used to control interactions between the 'web browser'(user agent)&nbsp;and the 'web page' through 'the DOM'(api) and has evolved into a language that <span style="text-decoration: underline;">has been used to write complete applications</span> and is also <span style="text-decoration: underline;">being used outside of the web browser environment</span>.&nbsp;(nodeJs, couchDB)</li>
<li>] Brendan Eich originally wrote the language named Livescript while working at Netscape in 1996. It was later renamed to JavaScript.</li>
</ol>
<h2>[WHY javascript pros ]</h2>
<ol>
<li><strong>] js is the most popular/widely used programming language in the world</strong></li>
<ol>
<li>] view source = countless examples, 1m+ tutorials,</li>
<li>] because of its origins in the browser and the phenomonal growth and adoption of the web, javascript is likely the most widely used, distributed and developed programming language in existance currently.</li>
<li>] js is now getting embedded into different devices besides just web browsers</li>
<ol>
<li>] set top boxes -</li>
<li>] ...</li>
</ol></ol>
<li><strong>] (almost) everything you ever wanted to know about js is available on the internet for free<br /></strong></li>
<ol>
<li>] tutorials, ] books, ] examples ] demos&nbsp; , ] courses, ] libraries, ] widgets ] frameworks, ] tools</li>
</ol>
<li><strong>] js shares a 'c' like syntax that is common to many programming languages</strong></li>
<ol>
<li>] other 'c like' programming languages including c, c++, c#, java,</li>
<li>] if you are starting your development journey and js is your first language this will benefit you later on, as you learn other languages that use similar syntax, coding conventions</li>
<li>] if your coming to js from another language, then you will already be familiar with it syntax</li>
</ol>
<li><strong>] js gets better with ajax</strong></li>
<ol>
<li>] enables developers to update just parts of a web page&nbsp;resulting in better user experience</li>
</ol>
<li><strong>] js gets better with 'libraries' like 'jquery'</strong></li>
<ol>
<li>] enables developers to abstract away the 'differences' between different dom implementations</li>
</ol>
<li><strong>] js gets better with 'frameworks' like 'angularjs' <br /></strong></li>
<ol>
<li>] enables developers to expedite application development by providing a framework of patterns, boilerplate code</li>
</ol>
<li><strong>] ecmascript 262.6 is coming soon</strong></li>
<ol>
<li>] the language is being signifigantly revised in the next revision adding Classes, Promises and more ...</li>
</ol>
<li><strong>] js has no overhead - getting started with js is uber easy</strong><ol>
<li>] if you(your computer) has&nbsp;a web browser and&nbsp;a text editor - you are ready to start coding with javascript.</li>
<li>] no compiler, no ide, no class libraries</li>
</ol></li>
</ol>
<h2>[WHY NOT javascript cons]</h2>
<ol>
<li><strong>] js is slow (an interpreted language)</strong></li>
<ol>
<li>] the execution speed of javascript code is much slower() than that of compiled programming languages like c++</li>
</ol>
<li><strong>] js is NOT a real programming language</strong></li>
<ol>
<li>] used to be a common refrain amongst "real" programmers, today, not so much,</li>
</ol>
<li><strong>] js has some <span style="text-decoration: line-through;">fatal</span> flaws</strong></li>
<ol>
<li>] yes indeed,</li>
</ol></ol>
<h2>[WHERE]</h2>
<ol>
<li>] on any html page where<strong> you want to have client side interactivity between your user and your web page,</strong> code blocks lie in a seperate js file OR&nbsp;within script tags with the head of the document OR inline script tags within the body of a document</li>
</ol>
<h2>[WHEN]</h2>
<ol>
<li><strong>]&nbsp;you want to have client side interactivity between your user and your web page,</strong></li>
<ol>
<li>] interactivity, between the user and the web page, &nbsp;] EX a user hovers over 'an element' and the element responds with a 'highlight' effect</li>
<li>] enhanced functionality like form validatio - &nbsp;] EX user enters data into a form feild and a js script checks that the&nbsp;'data entered'&nbsp;is valid for the use case</li>
</ol>
<li><strong>] you want to develop a web applications</strong></li>
<ol>
<li>]&nbsp;</li>
</ol></ol>
<h2>[EXAMPLE]</h2>
<ol>
<li><strong>] hello world</strong></li>
<ol>
<li>js-101 - 'script kiddy' - 101+ different, functional and interesting things you can do with js today intereactivity, validation, WITHOUT diving into the deep end.</li>
</ol>
<li><strong>] hello world</strong></li>
<ol>
<li>js-201 - 'professionalJS' - web application development - full blown javascript application development,</li>
</ol></ol>
<h2>[HOW-TO]</h2>
<ol>
<li><strong>] learning javascript</strong></li>
<ol>
<li>] prerequisite&nbsp;= learning programming - variables, data types, flow control, OOP,</li>
<li>]&nbsp;10 of the&nbsp;key 'concepts' you need to grok to master&nbsp;javascript -</li>
</ol></ol>
<h2>[REFERENCE]</h2>
<ol>
<li>] <a href="/view/article?id=1663" target="_blank">contents-javascript-library</a>&nbsp;</li>
<li>]&nbsp;<a href="http://en.wikipedia.org/wiki/Javascript">http://en.wikipedia.org/wiki/Javascript</a>&nbsp;- wikipedia article</li>
<li>] mozilla definition - see below&nbsp;</li>
</ol><hr />
<p>&nbsp;<span style="font-size: 10px;">- lightweight, </span></p>
<p>- It is a prototype-based, multi-paradigm scripting language that is dynamic, is type safe, and</p>
<p>?] dynamically typed</p>
<p>&nbsp;</p>
<hr />
<p>&nbsp;</p>
<ol>
<li><strong>]&nbsp;js vs ecmascript - compare and contrast</strong></li>
<ol>
<li>ecmascript - is the standard, defined by working/group committee(TC39)&nbsp;262.3, es5, es6</li>
<li>javascript - is&nbsp;an implementation of the standard by a particular vendor,</li>
<li>vendors - mozilla(spidermonkey), chrome(v8),</li>
</ol>
<li><strong>*] of note</strong></li>
<ol>
<li><strong>*]</strong>&nbsp;javascript has no relationship to the 'java' programming language</li>
<li>+] language heritage - scheme/lisp/</li>
<li>+] reputation - for a long time js suffered a poor reputation Amongst professional programmers/developers,</li>
<li>] scripting language VS programming language</li>
</ol></ol>

~ view article ~ Chapter] ch-001-introduction FROM [ Book] language-javascript IN [ libraries] technology-developer-www