关于编码格式

gbk，utf-8，utf-16,gb2312,iso-8859-1,unicode,ASCII,等有什么区别？？编程时候经常会有乱码现象，研究了半天，看了如下几个文章不自己再写了

 

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

http://www.ibm.com/developerworks/cn/java/j-lo-chinesecoding/

http://www./blog/2010/02/url_encoding.html

http://www.cnblogs.com/KevinYang/archive/2010/06/18/1760597.html