把包含字符串的文件转化为十六进制的形式，例如："ABCD" 转化后为“0x41 0x42 0x43”.-The document contains the string into hexadecimal form, such as: " ABCD" transformed to " 0x41 0x42 0x43" .

字符串转换成16进制数据，当网络编程时，经常需要把字符1（0x31）转换成hex的1（0x1），例如：mac地址-String into hexadecimal data, when network programming, we often need to transfer the character 1 (0x31) to convert hex to 1 (0x1), for example: mac address