JavaScript Advanced Programming Learning Note 01

Purely personal notes, all original, for reference only

Introduction to JavaScript in the first chapter

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-1.1 A brief History of JavaScript

Due to the limited speed of the network (only 28.8kbit/s) and the size of the Web page, the complexity of the gradual increase in the contradiction between the more intense. Netscape , at the forefront of technological innovation, decided to start developing a client-side language to deal with the problem. Brandon, who worked for Netscape, started planning to launch a scripting language called LiveScript on Netscape (Netscape Navigator 2) in February 1995 . Later on the eve of the release, Netscape, in order to catch the media stir Java's ride, temporarily renamed LiveScript to JavaScript.

JavaScript 1.0 has been a huge success, and Microsoft is jealous of the decision to invest more resources in its own product, IE , which competes with Netscape's browser. Shortly after JavaScript1.1 was released, Microsoft added a JavaScript implementation called JScript to its IE3 . This marks a significant step forward in the development of JavaScript as a language.

As Microsoft introduced its own version of JavaScript, it meant that there were several different versions of JavaScript , and JS did not have the same standard syntax and features as other programming languages at the time . so the standardization of JavaScript has been put on the agenda.

In 1997, a proposal modelled on JavaScript 1.1 was submitted to the European Association of Computer Manufacturers (ecma,european computer Manufacturers Association).  The ECMA designation Technical Committee No. 39th (TC39 , Technical Committee #39) is responsible for " standardizing the syntax and semantics of a common, cross-platform, vendor-neutral scripting language ".  * TC39 is made up of programmers from Netscape, Sun, Microsoft, Borland and other companies. after months of hard work, they completed the ECMA-262---Define a new scripting language called ECMAScript Standard. at this point, the browser developers began to use ECMAScript as the basis for their respective JAVASCRIPT implementations.

-1.2 JavaScript implementations

Although JavaScript and ECMAScript usually have the same meaning, JavaScript is much more expressive than ECMAScript. A complete JavaScript implementation consists of three parts:

• Core (ECMAScript)
• Document Object Model (DOM)
• Browser object Model (BOM)

Core (ECMAScript)

* There is actually no dependency between ECMAScript and Web browsers. A Web browser is just one of the ECMAScript hosting environments . The hosting environment not only provides the basic implementation of the language, but also

JavaScript Advanced Programming Learning Note 01