What does ECMAscript mean?

ECMAscript refers to a standard for JavaScript. It is a script programming language standardized by Ecma International through ECMA-262. This language is widely used on the World Wide Web. It is often called JavaScript or JScript.

The operating environment of this article: windows7 system, ECMAScript version 6, DELL G3 computer

What does ECMAscript refer to?

ECMAScript is a script programming language standardized by Ecma International (formerly the European Computer Manufacturers Association, the English name is European Computer Manufacturers Association) through ECMA-262. This language is widely used on the World Wide Web. It is often called JavaScript or JScript, so it can be understood as a standard for JavaScript, but in fact the latter two are implementations and extensions of the ECMA-262 standard.

Introduction

ECMAScript is a standardized specification for a scripting language developed by Brendan Edge of Netscape; originally named Mocha, and later renamed LiveScript , and finally renamed to JavaScript. In December 1995, Sun and Netscape jointly released JavaScript. In November 1996, Netscape submitted JavaScript to the European Computer Manufacturers Association for standardization. The first version of ECMA-262 was adopted by the Ecma organization in June 1997. ECMA Script is the name of the ECMA-262 standardized scripting language. Although JavaScript and JScript are compatible with ECMAScript, they contain functionality beyond ECMAScript.

ECMAScript is an object-based programming language that can perform calculations in a host environment and manipulate computable objects. ECMAScript was first designed as a Web scripting language to support the dynamic presentation of Web pages and provide server-side computing capabilities for Web-based client-server architectures. But as a scripting language, ECMAScript has the same nature as other scripting languages, that is, "used to manipulate, customize, and automate the functions provided by an existing system."

Keywords

ECMA-262 defines a set of keywords supported by ECMAScript that identify the beginning and/or end of an ECMAScript statement. By regulation, keywords are reserved and cannot be used as variable or function names. The following is the complete list of ECMAScript keywords:

break else new var typeof
case finally return void
catch for switch while
default if throw delete
in try do instanceof

If you use keywords as variable names or function names, you may get error messages such as "Identifier expected" (there should be an identifier).

Reserved words of ECMA-262

ECMAScript defines a set of reserved words. Reserved words are, in a sense, words reserved for the future. Therefore, reserved words cannot be used as variable or function names. The complete list of reserved words in ECMA-262 version 3 is as follows:

abstract enum int short
boolean export interface static
byte extends long super char final
native synchronized class float package
throws const goto private transient debugger
implements protected volatile double
import public

If a reserved word is used as a variable or function name, it is likely that future browsers will not accept it unless they implement the reserved word. to any error messages. When the browser implements this, the word is treated as a keyword, so a keyword error occurs.

In Netscape Navigator 2.0 released by Netscape in 1995, JavaScript 1.0, jointly developed with Sun, was released and was a great success, and JavaScript 1.1 was released in the subsequent 3.0 version, which happened to be when Microsoft entered the browser. In the market, IE 3.0 is equipped with a clone version of JavaScript - JScript, coupled with Cenvi's ScriptEase (also a client-side scripting language), resulting in three different versions of client-side scripting languages ​​existing at the same time. In order to establish standardization of the language, JavaScript 1.1 was submitted as a draft to the European Computer Manufacturers Association (ECMA) in 1997, and Technical Committee 39 (TC39) was appointed to "standardize a common, cross-platform, vendor-neutral script Grammatical and semantic standards of language”. Finally, ECMA-262 was formulated with the participation of Netscape, Sun, Microsoft, Borland and other companies. This standard defines a new scripting language called ECMAScript.

From now on, scripting languages ​​such as Javascript, JScript, and ActionScript are all implemented based on the ECMAScript standard.

So, ECMAScript is actually a standard for script syntax and semantics. In fact, JavaScript is composed of ECMAScript, DOM and BOM. Therefore, the syntax for declaring variables, operating arrays, etc. in JavaScript, JScript and ActionScript is exactly the same because they are all ECMAScript. However, they have their own unique methods in operating browser objects, etc. These are extensions of their respective languages.

Recommended study: "javascript basic tutorial"

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