This is the first day of my participation in the August More Text challenge.
What is JavaScript?
JavaScript is a scripting language that is dynamically typed, weakly typed, prototype-based. Its interpreter is called JavaScript engine, as part of the browser, widely used in client-side scripting language, was first used in HTML (standard Common Markup Language, an application) web pages, used to add dynamic features to HTML pages.
The birth of JavaScript
At first, the browser was only for browsing, not for interacting with visitors.
JavaScript, a web scripting language, solves the problem of browser interaction.
Why it’s called JavaScript
Taking advantage of Java’s popularity, LiveScript was temporarily renamed tO JavaScript, which has nothing to do with Java.
Who develops JavaScript primarily
Brendan Eich, a 34-year-old programmer, designed JavaScript in 10 days.
(1) Learn from the basic syntax of C language;
(2) Use the Java language for data types and memory management;
(3) Using Scheme language for reference, function is promoted to the status of first-class citizen;
(4) Reference Self language, based on prototype inheritance mechanism.
10 Design Flaws with Javascript
- Not suitable for developing large programs
- Very small standard library
- Null, and undefined
- Global variables are difficult to control
- Automatic insertion of end-of-line semicolons
- The plus operator
- NaN
- Distinction between arrays and objects
- = = and = = =
- Wrapper object of basic type
See: Ten Design Flaws of JavaScript for more details
ECMAScript is a what
ECMAScript is a scripting language standardized by Ecma International through ECMA-262.
ECMAScript, as defined by ECMA-262, has no dependency on Web browsers. In fact, the language itself does not contain input and output definitions.
Our common Web browser is just one possible hosting environment for an ECMAScript implementation. The host environment not only provides the basic ECMAScript implementation, but also provides extensions to the language for interfacing between the language and the environment.
What’s the ECMA – 262
Ecma International is an industry standards organization, and the standards it approves are Ecma – and then they can have other standards names. ECMAScript, which was created to allow the original JavaScript and JScript to follow the same set of standards, falls into the Ecma 262 standard, hence the ECMA-262 designation.
Historical version of ECMAScript
| version | time |
|---|---|
| ECMAScript 1.0 | 1997 |
| ECMAScript 2.0 | The 1998-06 |
| ECMAScript 3.0 | 1999-12 |
| ECMAScript 3.1 | The 2008-07 |
| ECMAScript 5.0 | 2009-12 |
| ECMAscript 5.1 | The 2011-06 |
| ECMAscript 6 | The 2015-06 |
JavaScript and ECMAScript
Although JavaScript and ECMAScript are often used by people to express the same meaning. But JavaScript means a lot more than ecMA-262 dictates.
A finished JavaScript implementation should consist of the following three distinct departments
-
Core ECMAScript: Describes the syntax and basic objects of the language
-
Document Object Model DOM: Provides methods and interfaces for working with web page content
The core objects are Window, Node, etc
-
Browser object model BOM: Provides methods and interfaces for interacting with browsers
The node and javascript
node = ECMAScript + nodejs API
javascript = ECMAScript + web API
Detail the history of JavaScript
Ten Design flaws of JavaScript
Why is ECMAscript standard called ECMA-262?
JavaScript Advanced Programming (version 3)