深入理解JavaScript编程：第二版

需积分: 10 37 浏览量更新于2024-07-21 收藏 2.89MB PDF 举报

"javascript 编程精解第二版（英文）—— Marijn Haverbeke" 《Eloquent JavaScript》是JavaScript编程领域的一本经典著作，由Marijn Haverbeke撰写，第二版提供了对现代编程的深入介绍。本书旨在帮助读者理解和掌握JavaScript语言的核心概念，同时涵盖了许多高级主题，使得它成为初学者和经验丰富的开发者的宝贵资源。书中涵盖了以下几个重要的JavaScript知识点： 1. **基础语法**：包括变量、数据类型（如字符串、数字、布尔值、对象和数组）、控制流程（如条件语句、循环）以及函数的使用。 2. **函数和闭包**：深入解析JavaScript的函数概念，强调了函数作为一等公民的地位，以及闭包在代码封装和模块化中的作用。 3. **对象和原型**：讲解了JavaScript的面向对象特性，如何通过构造函数和原型链创建和操作对象。 4. **作用域和闭包**：详细解释了变量的作用域规则，以及闭包如何允许函数访问并保持对外部作用域状态的引用。 5. **正则表达式**：介绍了正则表达式的基础和高级用法，包括模式匹配、替换和分组等技巧。 6. **异步编程**：讲解了事件循环和回调函数，以及Promise和async/await等现代异步处理方法。 7. **模块系统**：讨论了如何组织和导入/导出代码，包括CommonJS和ES模块（ES6）的使用。 8. **DOM操作**：讲述了如何使用JavaScript与网页的HTML和CSS进行交互，实现动态效果和用户交互。 9. **错误处理**：介绍了错误处理机制，包括try/catch语句和异常处理。 10. **调试技巧**：教授如何使用开发者工具来调试JavaScript代码，找出并修复问题。 11. **性能优化**：提到了性能考量和优化技术，如何编写高效的JavaScript代码。 12. **Web APIs**：涵盖了与浏览器交互的相关API，如Ajax、WebSocket和Web存储。 13. **Node.js**：简单介绍了Node.js环境，以及如何在服务器端使用JavaScript。 14. **高级话题**：包括递归、尾调用优化、函数式编程和元编程等进阶主题。 15. **游戏编程**：通过一个实际的项目案例，演示如何使用JavaScript开发简单的游戏。 16. **像素艺术**：介绍了一种使用JavaScript创作像素艺术的方法，展示了JavaScript在图形和艺术创作中的应用。此外，本书采用Creative Commons Attribution-NonCommercial许可证，允许非商业性的复制和分享，代码部分遵循MIT许可证，这意味着你可以自由地学习、使用和修改书中的示例代码。最后，作者特别感谢454位资助者对第二版的支持，并提供了一个由NoStarchPress出版的印刷版，包含额外的章节，可以在亚马逊购买。这本英文版的《Eloquent JavaScript》对于想要深入理解JavaScript的程序员来说是一本不可或缺的参考书籍。

grammer into all kinds of confusion, but that only means you should

proceed with caution and keep your wits about you. As you learn, there

will always be new challenges and new territory to explore. Program-

mers who refuse to keep exploring will stagnate, forget their joy, and get

bored with their craft.

Why language matters

In the beginning, at the birth of computing, there were no programming

languages. Programs looked something like this:

001 100 01 000 000 00 000 000 00

001 100 01 000 000 01 000 000 01

001 100 11 000 000 01 000 000 10

010 100 01 000 010 11 000 000 10

001 000 10 000 000 10 000 010 00

010 000 11 000 000 01 000 000 00

010 000 01 000 000 01 000 000 01

000 100 00 000 000 10 000 000 00

011 000 10 000 000 00 000 000 00

That is a program to add the numbers from 1 to 10 together and print

out the result: 1 + 2 + ... + 10 = 55. It could run on a simple, hypo-

thetical machine. To program early computers, it was necessary to set

large arrays of switches in the right position or punch holes in strips of

cardboard and feed them to the computer. You can probably imagine

how tedious and error-prone this procedure was. Even writing simple

programs required much cleverness and discipline. Complex ones were

nearly inconceivable.

Of course, manually entering these arcane patterns of bits (the ones

and zeros) did give the programmer a profound sense of being a mighty

wizard. And that has to be worth something in terms of job satisfaction.

Each line of the previous program contains a single instruction. It

could be written in English like this:

1. Store the number 0 in m emor y l oca tio n 0.

2. Store the number 1 in m emor y l oca tio n 1.

3. Store the value of memo ry loca tion 1 in memory location 2.

4. Subt rac t the n umber 11 from the v alue in mem ory loc ati on 2.

What is JavaScript?

JavaScript was introduced in 1995 as a way to add programs to web pages

in the Netscape Navigator browser. The language has since been adopted

by all other major graphical web browsers. It has made modern web

applications possible, applications with which you can interact directly,

without doing a page reload for every action. But it is also used in

more traditional websites to provide various forms of interactivity and

cleverness.

It is important to note that JavaScript has almost nothing to do

with the programming language named Java. The similar name was in-

spired by marketing considerations, rather than good judgment. When

JavaScript was being introduced, the Java language was being heavily

marketed and was gaining in popularity. Someone thought it a good

idea to try to ride along on this success. Now we are stuck with the

name.

After its adoption outside of Netscape, a standard document was writ-

ten to describe the way the JavaScript language should work to make

sure the various pieces of software that claimed to support JavaScript

were actually talking about the same language. This is called the EC-

MAScript standard, after the Ecma International organization that did

the standardization. In practice, the terms ECMAScript and JavaScript

can be used interchangeably—they are two names for the same language.

There are those who will say terrible things about the JavaScript lan-

guage. Many of these things are true. When I was required to write

something in JavaScript for the ﬁrst time, I quickly came to despise it.

It would accept almost anything I typed but interpret it in a way that

was completely diﬀerent from what I meant. This had a lot to do with

the fact that I did not have a clue what I was doing, of course, but there

is a real issue here: JavaScript is ridiculously liberal in what it allows.

The idea behind this design was that it would make programming in

JavaScript easier for beginners. In actuality, it mostly makes ﬁnding

problems in your programs harder because the system will not point

them out to you.

This ﬂexibility also has its advantages, though. It leaves space for a

lot of techniques that are impossible in more rigid languages, and as you

will see, for example, in Chapter 10, it can be used to overcome some

of JavaScript’s shortcomings. After learning the language properly and

working with it for a while, I have learned to actually like JavaScript.

There have been several versions of JavaScript. ECMAScript version

3 was the dominant, widely supported version in the time of JavaScript’s

ascent to dominance, roughly between 2000 and 2010. During this time,

work was underway on an ambitious version 4, which planned a number

of radical improvements and extensions to the language. Changing a

living, widely used language in such a radical way turned out to be

politically diﬃcult, and work on the fourth edition was abandoned in

2008, leading to the much less ambitious ﬁfth edition coming out in

2009. We’re now at the point where all major browsers support this ﬁfth

edition, which is the language version that this book will be focusing on.

A sixth edition is in the process of being ﬁnalized, and some browsers

are starting to support new features from this edition.

Web browsers are not the only platforms on which JavaScript is used.

Some databases, such as MongoDB and CouchDB, use JavaScript as

their scripting and query language. Several platforms for desktop and

server programming, most notably the Node.js project, the subject of

Chapter 20, are providing a powerful environment for programming

JavaScript outside of the browser.

Code, and what to do with it

Code is the text that makes up programs. Most chapters in this book

contain quite a lot of it. In my experience, reading code and writing code

are indispensable parts of learning to program, so try to not just glance

over the examples. Read them attentively and understand them. This

may be slow and confusing at ﬁrst, but I promise that you will quickly

get the hang of it. The same goes for the exercises. Don’t assume you

understand them until you’ve actually written a working solution.

I recommend you try your solutions to exercises in an actual JavaScript

interpreter. That way, you’ll get immediate feedback on whether what

you are doing is working, and, I hope, you’ll be tempted to experiment

and go beyond the exercises.

The easiest way to run the example code in the book, and to ex-

periment with it, is to look it up in the online version of the book at

剩余489页未读，继续阅读

mhp365

粉丝: 0
资源: 7

深入理解JavaScript编程：第二版

JavaScript 编程精解 中文第三版

《JAVASCRIPT编程精解 原书第2版》PDF

dram技术精解 第二版 中文

qt及qt quick开发实战精解 第二版pdf

dram技术精解(第二版 中文) ddr3_ddr4_ddr5_lpddr3_lpddr4_lpddr5.pdf

西门子1200编程实例精解pdf

c++ builder 5 高级编程实例精解 pdf

visaul c++6.0编程实例精解 pdf

c++ builder 5高级编程实例精解

dram技术精解(第二版 中文)

最新资源

JavaScript 编程精解中文第三版

《JAVASCRIPT编程精解原书第2版》PDF

dram技术精解第二版中文

qt及qt quick开发实战精解第二版pdf

dram技术精解(第二版中文) ddr3_ddr4_ddr5_lpddr3_lpddr4_lpddr5.pdf

dram技术精解(第二版中文)