[翻译]High Performance JavaScript(023)
Data Formats 数据格式
When considering data transmission techniques, you must take into account several factors: feature set, compatibility, performance, and direction (to or from the server). When considering data formats, the only scale you need for comparison is speed.
在考虑数据传输技术时，你必须考虑这些因素：功能集，兼容性，性能，和方向（发给服务器或者从服务器接收）。在考虑数据格式时，唯一需要比较的尺度的就是速度。
There isn't one data format that will always be better than the others. Depending on what data is being transferred and its intended use on the page, one might be faster to download, while another might be faster to parse. In this section, we create a widget for searching among users and implement it using each of the four major categories of data formats. This will require us to format a list of users on the server, pass it back to the browser, parse that list into a native JavaScript data structure, and search it for a given string. Each of the data formats will be compared based on the file size of the list, the speed of parsing it, and the ease with which it's formed on the server.
没有哪种数据格式会始终比其他格式更好。根据传送什么数据、用于页面上什么目的，某种格式可能下载更快，另一种格式可能解析更快。在本节中，我们创建了一个窗口小部件用于搜索用户信息并用四种主流的数据格式实现它。这要求我们在服务器端格式化一个用户列表，将它返回给浏览器，将列表解析成JavaScript数据格式，并搜索特定的字符串。每种数据格式将比较列表的文件大小，解析速度，和服务器上构造它们的难易程度。
XML
When Ajax first became popular, XML was the data format of choice. It had many things going for it: extreme interoperability (with excellent support on both the server side and the client side), strict formatting, and easy validation. JSON hadn't been formalized yet as an interchange format, and almost every language used on servers had a library available for working with XML.
&
相关文档：
玩PHP、Delphi、Java基本上都有对象，习惯这种思路后上手任何语言都想靠OO思路，这绝不是在赶时髦，而是把相关代码进行内聚的确可以体会到维护的方便！
在JavaScript中如何创建对象？
JavaScript是基于对象的！它也是以Object为根类，其它类继承之。在根类提供了几个方法。供继承类使用！
以下是创建对象的例子：
funct ......
typeof 是JavaScript的运算符
——返回一个用来表示表达式的数据类型的字符串
typeof[(] expression [)] //typeof语法中的圆括号是可选项
typeof 运算符@import url(../html-vss/msdnie4a.css);
typeof
运算符把类型信息当作字符串返回。typeof
返回值有� ......
第四章 Algorithms and Flow Control 算法和流程控制
The overall structure of your code is one of the main determinants as to how fast it will execute. Having a very small amount of code doesn't necessarily mean that it will run quickly, and having a large amount of code ......
Conditionals 条件表达式
Similar in nature to loops, conditionals determine how execution flows through JavaScript. The traditional argument of whether to use if-else statements or a switch statement applies to JavaScript just as it does to other languages. Since different b ......
A Note on Benchmarking 测试基准说明
Because a regex's performance can be wildly different depending on the text it's applied to, there's no straightforward way to benchmark regexes against each other. For the best result, you need to benchmark your regexes on test strings o ......
