ASCII(American Standard Code for Information Interchange，美國(guó)信息交換標(biāo)準(zhǔn)代碼)是一種字符編碼系統(tǒng)，它基于拉丁字母。ASCII 使用 7 位二進(jìn)制數(shù)(即 0 到 127)來表示字符。以下是 ASCII 碼的一部分對(duì)照表：

Dec Hex Char Dec Hex Char
--- --- ---- --- --- ----
0 00 NUL(null) 64 40 @
1 01 SOH(start of heading) 65 41 A
2 02 STX(start of text) 66 42 B
3 03 ETX(end of text) 67 43 C
4 04 EOT(end of transmission) 68 44 D
5 05 ENQ(enquiry) 69 45 E
6 06 ACK(acknowledge) 70 46 F
7 07 BEL(bell) 71 47 G
8 08 BS (backspace) 72 48 H
9 09 TAB(tab) 73 49 I
10 0A LF (NL line feed, new line) 74 4A J
11 0B VT (vertical tab) 75 4B K
12 0C FF (NP form feed, new page) 76 4C L
13 0D CR (carriage return) 77 4D M
14 0E SO (shift out) 78 4E N
15 0F SI (shift in) 79 4F O
16 10 DLE(data link escape) 80 50 P
... ... ...
32 20 Space 96 60 `
33 21 ! 97 61 a
34 22 " 98 62 b
35 23 # 99 63 c
36 24 $ 100 64 d
37 25 % 101 65 e
38 26 & 102 66 f
39 27 ' 103 67 g
40 28 ( 104 68 h
41 29 ) 105 69 i
42 2A * 106 6A j
43 2B + 107 6B k
44 2C , 108 6C l
45 2D - 109 6D m
46 2E . 110 6E n
47 2F / 111 6F o
48 30 0 112 70 p
49 31 1 113 71 q
50 32 2 114 72 r
... ... ...
57 39 9 121