How many bytes does one ascii character occupy?

One ascii character occupies 1 byte. ASCII code characters are represented by 7-bit or 8-bit binary encoding in the computer and are stored in one byte, that is, one ASCII code occupies one byte. ASCII code can be divided into standard ASCII code and extended ASCII code. Standard ASCII code is also called basic ASCII code. It uses 7-bit binary numbers (the remaining 1 binary digit is 0) to represent all uppercase and lowercase letters, and the numbers 0 to 9. Punctuation marks, and special control characters used in American English.

The operating environment of this tutorial: Windows 7 system, Dell G3 computer.

ASCII (American Standard Code for Information Interchange): The 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.

ASCII code uses a specified 7-bit or 8-bit binary number combination to represent 128 or 256 possible characters.

ASCII code characters are represented by 7-bit or 8-bit binary encoding in the computer and are stored in one byte, that is, one ASCII code occupies one byte.

ASCII code can be divided into standard ASCII code and extended ASCII code.

Standard ASCII code is also called basic ASCII code, which uses 7 binary digits (the remaining 1 binary digit is 0) to represent all uppercase and lowercase letters, the number 0 to 9, punctuation, and special control characters used in American English. Among them:

• 0~31 and 127 (33 in total) are control characters or special communication characters (the rest are displayable characters)

  For example, the control character: LF ( Line feed), CR (carriage return), FF (page feed), DEL (delete), BS (backspace), BEL (ring), etc.;

  Special characters for communication: SOH (header), EOT (End of text), ACK (confirmation), etc.;

  ASCII values 8, 9, 10 and 13 are converted into 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.

Also note that in standard ASCII, its highest bit (b7) is used as a parity bit. The so-called parity check refers to a method used to check whether errors occur during code transmission. It is generally divided into two types: odd check and even check. Odd parity rules: the number of 1's in a byte of the correct code must be an odd number. If it is not an odd number, add 1 to the highest bit b7; even parity rules: the number of 1's in a byte of the correct code must be an even number. , if it is not an even number, add 1 to the highest bit b7.

The last 128 characters are called extended ASCII codes.Many x86-based systems support the use of extended (or "high") ASCII. Extended ASCII allows the 8th bit of each character to be used to determine an additional 128 special symbol characters, foreign letters, and graphic symbols.

The ASCII code standard table is as follows

##STX (start of text) Text begins ##0000 0011 0000 0100 0000 0101 0000 0110 0000 0111 ##BEL (bell) ring 010 011 012 013 ##16 0x10 0001 0001 0001 0010 ##0x13 DC3 (device control 3) Device control 3 024 ##CAN (cancel) Cancel 0001 1001 031 25 0x19 EM (end of medium) End of medium 0001 1010 032 26 0x1A SUB (substitute) instead of 0001 1011 033 27 ##0001 1100 0001 1101 ##GS (group separator) Grouping symbol 036 30 0x1E RS (record separator) Record separator 037 31 0x1F US (unit separator) Unit separator ##040 ##0010 0001 041 34 ##0010 0011 043 35 0x23 0010 0100 044 36 0x24 0010 0101 0010 0110 0010 0111 ##0010 1000 0010 1001 ##0x2A * 星 053 43 0x2B ##054 0010 1101 ##0x2D - ##. Period 0010 1111 057 47 0x2F / slash 0011 0000 060 48 0x30 0 Characters 0 ##0011 0001 ##51 0x33 3 ##0011 0100 064 ##5 ##066 54 0x38 8 Character 8 ##61 0x3D = equal sign 0011 1110 076 0011 1111 ##? Question mark 0100 64 0x40 @ Email symbol 0101 65 ##0100 0010 0102 ##67 0x43 C uppercase letter C ##E uppercase letter E 0100 0110 0106 70 0x46 F Capital letter F 0100 0111 0107 71 ##0100 1000 0111 73 0x49 I uppercase letter I 0112 0113 76 0x4C 77 0100 1110 0116 78 ##uppercase letters O 0101 0000 0120 80 0x50 P 0101 0001 0101 0010 ##0x52 R Capital R ##0123 ##0124 ##85 0x55 U upper case U 86 87 ##88 0101 1001 0131 ##0x59 Y Capital letter Y ##91 0x5B [ 0101 1100 ##0136 94 0x5E ^ 0137 97 ##98 ##0x63 0x64 ##0110 0111 0147 103 0x67 g lower case g 0110 1000 0150 104 0x68 h lowercase h ##0110 1001 0153 107 0x6B k 0154 0110 1101 0155 ##n 111 0111 0000 0160 ##0x71 q lower case q 0111 0010 0162 114 ##0163 115 0x73 s lowercase s 0164 116 0x74 t lower case t 0165 ##0x78 x Lower case x 121 ##0111 1010 ##0111 1100 0174 ##0177 ##Size rules

ASCII table

Bin (binary)	Oct (octal)	Dec (decimal)	Hex (Hex)	Abbreviation/Character	Explanation
##0000 0000	00	0	0x00	NUL(null)	null character
0000 0001	01	1	0x01	SOH(start of headline)	Title start
0000 0010	02	2	##0x02
03	3	0x03	ETX (end of text)	End of text
04	4	0x04	EOT (end of transmission)	End of transmission
05	5	##0x05	ENQ (enquiry)	Request
06	6	0x06	ACK (acknowledge)	Notification received
07	7	##0x07			##0000 1000
8	0x08	BS (backspace)	Backspace		0000 1001
9	0x09	HT (horizontal tab)	Horizontal tab character		0000 1010
10	0x0A	LF (NL line feed, new line)	Line feed key		0000 1011
11	##0x0B	VT (vertical tab)	Vertical tab character	##0000 1100	014
12	0x0C	FF (NP form feed, new page )	Page key	##0000 1101	015	13	##0x0D	CR ( carriage return)	Enter key
0000 1110	016	14	0x0E	SO (shift out)	No need to switch
0000 1111	017	15	0x0F	SI (shift in)	Enable switching
0001 0000	020		##DLE (data link escape)	Data link escape
021	17	0x11	DC1 (device control 1)	Device control 1
##022	##18	0x12	DC2 (device control 2)	Device control 2	0001 0011
023	19				##0001 0100
20	0x14	##DC4 (device control 4)	Device Control 4	##0001 0101	025
21	0x15	NAK (negative acknowledge)	Refuse to accept	0001 0110	026
22	0x16	SYN (synchronous idle)	synchronous idle	0001 0111	027
23	0x17	ETB (end of trans. block)	End transmission block
0001 1000	##030	24	0x18
		##0x1B	ESC (escape)	Escape (overflow)
034	28	0x1C	FS (file separator)	File delimiter
##035	29	0x1D			0001 1110
					0001 1111
					0010 0000
32	0x20	(space)	space
33	##0x21	!	Exclamation mark	##0010 0010	##042
##0x22	"	##Double quotes
			##$	dollar sign
045	37	0x25	%	Percent sign
046	38	0x26	&	和
047	39	0x27	'	Close single quotes
050	40	0x28	(	open bracket
051	41	0x29	)	Closing bracket	##0010 1010
052	42				0010 1011
			##plus sign		0010 1100
44	0x2C	,	comma		##055
45			Minus sign/dash
0010 1110	056	46	##0x2E
061	49	##0x31	1	Character 1	##0011 0010
062	50	0x32	2	Character 2	0011 0011
063			##Character 3
52	##0x34	4	Characters 4	0011 0101	065
53	0x35	##Character 5		0011 0110
0x36	6	##Characters 6	0011 0111	067	55
0x37	7	Characters 7	##0011 1000	070	56
0011 1001	071	57	0x39	9	Characters 9
0011 1010	072	58	0x3A	:	Colon
##0011 1011	073	59	0x3B	;	Semicolon
0011 1100	074	60	0x3C		is less than
0011 1101	075
	##62	##0x3E	>	is greater than
##077	63	0x3F			0100 0000
					0100 0001
	##0x41	A	Capital Letter A
66	0x42	B	Capital B	##0100 0011	0103
				0100 0100	0104	68	##0x44	D	Capital D
0100 0101	0105	69	0x45
		##0x47	G	Capital G
##0110	72	0x48	H	uppercaseH	##0100 1001
					01001010
##74	0x4A	J	Capital J		0100 1011
##75	##0x4B	K	Capital K	0100 1100	##0114
	##L	uppercase L		0100 1101	0115
0x4D	M	##Capital letter M
0x4E	N	uppercase letter N	##0100 1111	0117	79	0x4F	##O
				##upper case P
0121	##81	0x51	Q	Capital letter Q
0122	##82				0101 0011
83	0x53	S	uppercase S		0101 0100
84	0x54	T	##Capital letter T	0101 0101	0125
				##0101 0110	0126
0x56	V	Capital V		0101 0111	0127
0x57	W	uppercase letter W		0101 1000	0130
0x58	X	Capital letter X			##89
			##0101 1010	0132	90	0x5A	Z	##Capital letter Z
0101 1011	0133			##Open square brackets
0134	##92	##0x5C	\	Backslash	0101 1101
0135	93	0x5D	]	Closing square bracket	0101 1110
			##Caret		0101 1111
95	##0x5F	_	underscore	##0110 0000	0140
96	0x60	`	Open single quotes	##0110 0001	##0141
0x61	a	lower case a		0110 0010	0142
0x62	##b	lowercase b	##0110 0011	0143	99
c	lower case c		0110 0100	0144	100
##d	##lower case d	0110 0101	0145	101	0x65	e	lower case e
##0110 0110	0146	102	0x66	f	lower case f
0151	105	0x69	i	##lower case i	##0110 1010
0152	106	0x6A	j	Lower case j	##0110 1011
			##lower case k		0110 1100
108	##0x6C	l	lowercase l
109	##0x6D	m	lower case m	0110 1110	0156
110	0x6E	##lowercase n		0110 1111	0157
0x6F	o	##lowercase o			##112
0x70	p	lower case p
0111 0001	0161	##113
		##0x72	##r	##lowercase r	0111 0011
					0111 0100
					##0111 0101
117	##0x75	##u	lowercase u	0111 0110	0166
118	0x76	v	lower case v	0111 0111	0167
119	0x77	w	lowercase w	0111 1000	0170
120				##0111 1001	0171
0x79	y	Lower case y		##0172	122
0x7A	z	lower case z	0111 1011	0173	123
0x7B	{	##Opening brackets
	##124	##0x7C	|	vertical line	##0111 1101
0175	125	0x7D	}	Closing curly brace	0111 1110
0176	126	0x7E	~	tilde	0111 1111
##127	##0x7F	DEL (delete)	Delete		Common ASCII code size rules: numbers

Numbers are smaller than letters. For example, "7" The number 0 is smaller than the number 9, and increases in sequence from 0 to 9. For example, "3"

• The letter A is smaller than the letter Z, and increases in order from A to Z. For example, "A"
• The uppercase letters of the same letter are 32 smaller than the lowercase letters. Such as "A"
• The ASCII code sizes of several common letters: "A" is 65; "a" is 97; "0" is 48.
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