字符编码

refer :

字符编码笔记：ASCII，Unicode和UTF-8

http://www.ruanyifeng.com/blog/2007/10/ascii_unicode_and_utf-8.html 

http://www.joelonsoftware.com/articles/Unicode.html

 

Unicode与JavaScript详解

http://www.ruanyifeng.com/blog/2014/12/unicode.html