字符编码

• Provides options for changing the character encoding of the message
  提供用于更改消息的字符编码的选项。
• Class represents a character encoding
  类表示字符编码。
• Class for the specified stream , with the specified character encoding
  用指定的字符编码为指定的流初始化
• Unicode character encoding standard
  Unicode字符编码标准
• The htmlentities ( ) function converts characters to html entities
  函数的作用是：转换字符为html字符编码。
• Extended character encoding support
  扩展字符编码支持
• Class based on the supplied stream and a specific character encoding
  基于所提供的流和特定的字符编码，初始化
• The following character encodings can be specified in the encoding switch
  在编码开关中可以指定以下字符编码：
• The character encoding to use if encoding is not determined from file
  要在未从文件确定编码时使用的字符编码。
• The html _ entity _ decode ( ) function converts html entities to characters
  函数的作用是：转换html字符编码为字符。