Kidney Day Arch A Stroke JavaScript series Chapter0 Preface

Chapter 0 Preface

1. A brief History of JavaScript

1994 Netscape released the Navigator browser, due to the lack of interactivity at the time, so Netscape needed a scripting language for the Web to add interaction, but in what language, it is difficult to decide. However, the second year Sun released Java, its conquer posture, prompting Netscape to make a thigh-hugging decision, after Netscape and Sun Allied, Sun fully involved in scripting language development decisions.

Finally, Netscape decided to develop a simplified version of the Java language, and assign the task to Brendan Eich, but this guy is not interested in Java, in order to cope with the job, he took only two weeks to design the JavaScript.

His basic design ideas are:

(1) Learn the basic grammar of C language;

(2) Learn the Java language data type and memory management;

(3) using the scheme language to promote the function to the status of "first Class citizen";

(4) Using the Self language, use the inheritance mechanism based on prototype (prototype).

The synthesis of multi-party decision making JavaScript become a product of hybridization.

In 1996, Microsoft finally realized the importance of the Internet and increased its support for home browser ie, including JScript, so there were two different JavaScript versions on the market at a time. This historical source heralds the untold pain that later programmers have endured to deal with compatibility issues.

Finally, in 1997, the European Association of Computer Manufacturers (ECMA) developed the standard ECMA-262 (aka ECMAScript) for JavaScript, and various browser vendors began to use the standard as the basis for their own browser scripts.

ECMAScript so far, a total of 6 releases, (2009 release of the fifth edition, 2016 release sixth edition).

Reference: http://www.ruanyifeng.com/blog/2011/06/birth_of_javascript.html

2. Using JavaScript in HTML

2.1 External Scripts

<script type = "Text/javascript" src = "url" ></script>

In addition to the type and SRC, the label has other properties, such as:

Async = "Async" Asynchronous script. means download the script now, but do not block other operations.

defer = "defer" delay script. Indicates that the download is immediate, but the script is executed until the entire document has been resolved. for external scripts.

Quotation marks can be either a relative or an absolute path.

When async or defer is not set, the browser is parsed in the order in which the script is arranged.

As for the location of <script>, the modern front-end approach is to put it before </body>.

2.2 Embedded Scripts

Write scripts directly in the <script></script> tab.

3. JavaScript knowledge system and the directory structure of this series

This series is to JS two authoritative books "JavaScript Advanced Programming (3rd Edition)" (referred to as "advanced") and "JavaScript authoritative Guide (6th edition)" (hereinafter referred to as "authority") and other information refining, carding and summary.

This series will often use English annotations to increase the clarity of ideographic.

JavaScript knowledge Map	Language	ECMAScript
	Client-side	Bom
		Dom
		Others
	Transmition	Ajax, JSON
	Server-side	Node ...

javascript Vertical ecology	Application layer	Span style= "FONT-SIZE:16PX;" > interactive logic
	component layer	custom components
		generic components, such as DatePicker ...
	frame layer	Span style= "FONT-SIZE:16PX;" >jquery, Angular, React ...
	core layer	Span style= "FONT-SIZE:16PX;" > Native JS and underlying API

Language
The 0th chapter: Preface	A brief history of JavaScript, JavaScript knowledge system
Chapter One: Grammar	Grammar Brief
Chapter II: Values and variables	Six types of values, type conversions, variable descriptions
Chapter III: Operators and expressions	Various types of operators and expressions
Fourth Chapter: statement	conditions, loops
Fifth chapter: Functions	function analysis, scope, closure, this object, recursion, etc.
Sixth chapter: Objects	Object description, properties and methods of various JavaScript preset objects
The seventh chapter: Object-Oriented Programming	Various methods for creating objects, inheritance between objects
Client
Eighth chapter: BOM	Properties and methods for various BOM objects
Nineth Chapter: DOM	Properties and methods of various DOM objects, events, form scripts, etc.
Tenth chapter: Other Client Technologies	Client detection, security, storage, JS execution principle, etc.
Transmission
11th Chapter: Data transmission	Ajax, JSON, etc.
Service side
12th Chapter: Server-side scripting	node, etc.
Other
The 13th chapter: Regular Expressions	Rules, how to use
The 14th chapter: Modularization	Modularization thought and its process of technological evolution
15th Chapter: Graphics	Canvas, SVG, etc.
The 16th chapter: ES6 's new things	New Points of knowledge

Kidney Day Arch A Stroke JavaScript series Chapter0 Preface