ASCII ((American Standard Code for Information Interchange): American Standard Code for Information Interchange) is a computer coding system based on the Latin alphabet, mainly used to display modern English and other Western European languages. It is the most common information exchange standard and is equivalent to the international standard ISO/IEC 646. ASCII was first published as a standard type in 1967, and was last updated in 1986. So far, a total of 128 characters have been defined.
The ASCII code of character 0 is 48, and the ASCII code of character 9 is 57.
ASCII codes 48 to 57 are ten Arabic numerals from 0 to 9.
0~31 and 127 (33 in total) are control characters or communication-specific characters (the rest are displayable characters), such as control characters: LF (line feed), CR (carriage return), FF (form feed) ), DEL (delete), BS (backspace), BEL (ring), etc.; communication special characters: SOH (head of text), EOT (end of text), ACK (confirmation), etc.
ASCII values 8, 9, 10 and 13 are converted to backspace, tab, line feed and carriage return characters respectively. They do not have a specific graphic display, but will have different effects on text display depending on the application.
32~126 (95 in total) are characters (32 is a space), of which 48~57 are ten Arabic numerals from 0 to 9.
65~90 are 26 uppercase English letters, 97~122 are 26 lowercase English letters, and the rest are some punctuation marks, arithmetic symbols, etc.
Size rules
Common ASCII code size rules: 0~9 1) Numbers are smaller than letters. Such as "7" < "F"; 2) The number 0 is smaller than the number 9, and increases in sequence from 0 to 9. For example, "3" < "8"; 3) The letter A is smaller than the letter Z, and increases in order from A to Z. For example, "A" < "Z"; 4) The uppercase letters of the same letter are 32 smaller than the lowercase letters. Such as "A"<"a". The ASCII code sizes of several common letters: "A" is 65; "a" is 97; "0" is 48. For more related knowledge, please pay attention to PHP Chinese website! ! The above is the detailed content of What is the ASCII code for character 9?. For more information, please follow other related articles on the PHP Chinese website!