字符编码ASCII,Unicode和UTF-8详解（Character encoding, ASCII, Unicode, and UTF-8）.doc

字符编码ASCII,Unicode和UTF-8详解（Character encoding, ASCII, Unicode, and UTF-8） This noon, I suddenly wanted to find out the relationship between Unicode and UTF-8, so I began to check the information on the internet. As a result, this problem is more complicated than I expected. Its only 9 oclock since lunch time. Here are my notes, mainly to sort out my thoughts. But I try to write it in a straightforward way, in the hope that it will be useful to other friends. After all, character encoding is the cornerstone of computer technology, and you have to know a little bit of coding knowledge if you want to be proficient in using a computer. 1. ASCII code We know that within the computer, all the information is eventually represented as a binary string. Each binary bit (bit) has 0 and 1 states, so the eight binary bits can be combined into 256 States, called (byte). That is to say, a byte can be used to represent 256 different states, each corresponding to one symbol, i.e., 256 symbols, from 0000000 to In the 60s of the last century, the United States developed a set of character encoding, and made a uniform stipulation on the relationship between English characters and binary digits. This is called ASCII code, has been used so far. The ASCII code specifies a total of 128 characters, such as the space SPACE is 32 (binary, and the uppercase letter A is 65 (binary. These 128 symbols, including 32 printed symbols that cannot be printed, take up only one byte of the latter 7 bits, and the first 1 are uniformly specified as 0. 2, non ASCII encoding It is enough to encode English with 128 symbols, but it is not enough to represent other languages and 128 symbols. For example, in French, with phonetic symbols above a letter, it will not be able to use ASCII code. As a result, some European countries decided to make new symbols using the highest bits of inactivity in bytes. For example, in French type encoding is 130 (binary. As a result, the co