Stack Overflow
Stack Overflow

Questions tagged [ascii]

A character-encoding scheme based on the ordering of the English alphabet. ASCII stands for American Standard Code for Information Interchange.

ASCII codes represent text in computers, communications equipment, and other devices that use text. Most modern character-encoding schemes are based on ASCII, though they support many more characters than did ASCII.

ASCII includes definitions for 128 characters: 33 are non-printing control characters (now mostly obsolete) that affect how text and space is processed; 94 are printable characters, and the space is considered an invisible graphic. The most commonly used character encoding on the World Wide Web was US-ASCII until December 2007, when it was surpassed by UTF-8.

The following table contains the 128 ASCII characters.

Char  Dec  Oct Hex | Char Dec  Oct Hex | Char Dec  Oct Hex | Char Dec  Oct  Hex
(nul)   0 0000 x00 | (sp)  32 0040 x20 | @     64 0100 x40 | `      96 0140 x60
(soh)   1 0001 x01 | !     33 0041 x21 | A     65 0101 x41 | a      97 0141 x61
(stx)   2 0002 x02 | "     34 0042 x22 | B     66 0102 x42 | b      98 0142 x62
(etx)   3 0003 x03 | #     35 0043 x23 | C     67 0103 x43 | c      99 0143 x63
(eot)   4 0004 x04 | $     36 0044 x24 | D     68 0104 x44 | d     100 0144 x64
(enq)   5 0005 x05 | %     37 0045 x25 | E     69 0105 x45 | e     101 0145 x65
(ack)   6 0006 x06 | &     38 0046 x26 | F     70 0106 x46 | f     102 0146 x66
(bel)   7 0007 x07 | '     39 0047 x27 | G     71 0107 x47 | g     103 0147 x67
(bs)    8 0010 x08 | (     40 0050 x28 | H     72 0110 x48 | h     104 0150 x68
(ht)    9 0011 x09 | )     41 0051 x29 | I     73 0111 x49 | i     105 0151 x69
(nl)   10 0012 x0a | *     42 0052 x2a | J     74 0112 x4a | j     106 0152 x6a
(vt)   11 0013 x0b | +     43 0053 x2b | K     75 0113 x4b | k     107 0153 x6b
(np)   12 0014 x0c | ,     44 0054 x2c | L     76 0114 x4c | l     108 0154 x6c
(cr)   13 0015 x0d | -     45 0055 x2d | M     77 0115 x4d | m     109 0155 x6d
(so)   14 0016 x0e | .     46 0056 x2e | N     78 0116 x4e | n     110 0156 x6e
(si)   15 0017 x0f | /     47 0057 x2f | O     79 0117 x4f | o     111 0157 x6f
(dle)  16 0020 x10 | 0     48 0060 x30 | P     80 0120 x50 | p     112 0160 x70
(dc1)  17 0021 x11 | 1     49 0061 x31 | Q     81 0121 x51 | q     113 0161 x71
(dc2)  18 0022 x12 | 2     50 0062 x32 | R     82 0122 x52 | r     114 0162 x72
(dc3)  19 0023 x13 | 3     51 0063 x33 | S     83 0123 x53 | s     115 0163 x73
(dc4)  20 0024 x14 | 4     52 0064 x34 | T     84 0124 x54 | t     116 0164 x74
(nak)  21 0025 x15 | 5     53 0065 x35 | U     85 0125 x55 | u     117 0165 x75
(syn)  22 0026 x16 | 6     54 0066 x36 | V     86 0126 x56 | v     118 0166 x76
(etb)  23 0027 x17 | 7     55 0067 x37 | W     87 0127 x57 | w     119 0167 x77
(can)  24 0030 x18 | 8     56 0070 x38 | X     88 0130 x58 | x     120 0170 x78
(em)   25 0031 x19 | 9     57 0071 x39 | Y     89 0131 x59 | y     121 0171 x79
(sub)  26 0032 x1a | :     58 0072 x3a | Z     90 0132 x5a | z     122 0172 x7a
(esc)  27 0033 x1b | ;     59 0073 x3b | [     91 0133 x5b | {     123 0173 x7b
(fs)   28 0034 x1c | <     60 0074 x3c | \     92 0134 x5c | |     124 0174 x7c
(gs)   29 0035 x1d | =     61 0075 x3d | ]     93 0135 x5d | }     125 0175 x7d
(rs)   30 0036 x1e | >     62 0076 x3e | ^     94 0136 x5e | ~     126 0176 x7e
(us)   31 0037 x1f | ?     63 0077 x3f | _     95 0137 x5f | (del) 127 0177 x7f
6938 questions
22
votes
1 answer

Are the character digits ['0'..'9'] required to have contiguous numeric values?

Must a C++ implementation set the chars '0'-'9' to have contiguous numeric values, i.e. so that: '0' -> 0+n '1' -> 1+n m -> m+n '9' -> 9+n I cannot find it mentioned in the documentation of isdigit ([classification] (22.3.3.1 Character…
Sebastian Mach
  • 38,570
  • 8
  • 95
  • 130
22
votes
1 answer

Can urls have UTF-8 characters?

I was curious if I should encode urls with ASCII or UTF-8. I was under the belief that urls cannot have non-ASCII characters, but someone told me they can have UTF-8, and I searched around and couldn't quite find which one is true. Does anyone know?
Popcorn
  • 5,188
  • 12
  • 54
  • 87
22
votes
4 answers

How to convert ASCII value into char in C++?

How do I convert 5 random ascii values into chars? Prompt: Randomly generate 5 ascii values from 97 to 122 (the ascii values for all of the alphabet). As you go, determine the letter that corresponds to each ascii value and output the word formed…
user2877477
  • 253
  • 1
  • 4
  • 8
22
votes
3 answers

How to fix UTF encoding for whitespaces?

In my C# code, I am extracting text from a PDF document. When I do that, I get a string that's in UTF-8 or Unicode encoding (I'm not sure which). When I use Encoding.UTF8.GetBytes(src); to convert it into a byte array, I notice that the whitespace…
omega
  • 40,311
  • 81
  • 251
  • 474
22
votes
2 answers

How are the ascii diagrams in RFC's generated?

Not sure if this is the correct stackexchange to ask this question, but I was wondering whether anyone knows if the ascii diagrams in http://tools.ietf.org/rfc/rfc5755.txt page 6 are handcrafted or generated using a program that takes the nodes and…
merlin2011
  • 71,677
  • 44
  • 195
  • 329
22
votes
6 answers

Why do my keystrokes turn into crazy characters after I dump a bunch of binary data into my terminal?

If I do something like: $ cat /bin/ls into my terminal, I understand why I see a bunch of binary data, representing the ls executable. But afterwards, when I get my prompt back, my own keystrokes look crazy. I type "a" and I get a weird diagonal…
raldi
  • 21,344
  • 33
  • 76
  • 86
21
votes
2 answers

Forcing Python json module to work with ASCII

I'm using json.dump() and json.load() to save/read a dictionary of strings to/from disk. The issue is that I can't have any of the strings in unicode. They seem to be in unicode no matter how I set the parameters to dump/load (including ensure_ascii…
meteoritepanama
  • 6,092
  • 14
  • 42
  • 55
21
votes
5 answers

Convert ASCII number to ASCII Character in C

In C is there a way to convert an ASCII value typed as an int into the the corresponding ASCII character as a char?
Anonymous
  • 219
  • 1
  • 2
  • 3
21
votes
4 answers

How to convert a string of hex values to a string?

Say I have a string like: string hex = "48656c6c6f"; Where every two characters correspond to the hex representation of their ASCII, value, eg: 0x48 0x65 0x6c 0x6c 0x6f = "Hello" So how can I get "hello" from "48656c6c6f" without having to create…
NullUserException
  • 83,810
  • 28
  • 209
  • 234
21
votes
2 answers

What does the "^@" mean in file?

Code: int fd; fd = open("fruit", O_WRONLY); write(fd, "apple", sizeof("apple")); close(fd); I compile it with $ gcc test.c -o test and run as $ ./test Then I open the fruit file, and I see the following in the file: apple^@ What does the ^@…
Ren
  • 2,852
  • 2
  • 23
  • 45
21
votes
1 answer

UnicodeEncodeError: 'ascii' codec can't encode character u'\xe4'

I permanently get the following error: UnicodeEncodeError: 'ascii' codec can't encode character u'\xe4' in position 27: ordinal not in range(128) I already tried x.encode("ascii", "ignore") x.encode("utf-8") x.decode("utf-8") However, nothing…
toom
  • 12,864
  • 27
  • 89
  • 128
21
votes
1 answer

Unmappable character for encoding ASCII but my files are in UTF-8

I have the following error launching my ant script: [javac] /****/TextUtils.java:25: error: unmappable character for encoding ASCII But this file is encoded in UTF-8, if i do the info command: /***/TextUtils.java: text/plain; charset=utf-8 Why is…
Jerome Ansia
  • 6,854
  • 11
  • 53
  • 99
20
votes
6 answers

Xoring alphabet letters with space character

Is there a historical reason as to why Xoring any alphabetic letter with the space character changes the case of the letter? (i.e., 'a' xor ' ' = 'A', 'F' xor ' ' = 'f', etc...) Or is this just a coincidence? (Assuming the characters are ASCII- or…
Aryan Naraghi
  • 273
  • 3
  • 6
20
votes
1 answer

What character can I use to display the "four arrows icon"?

What Unicode character can I use do display this character? I currently need it to write a .doc document, but I would like to know if a Unicode character is available, in order to print it out in an app, or if some font has this glyph in it.
gog
  • 1,220
  • 11
  • 30
20
votes
10 answers

Convert String from ASCII to EBCDIC in Java?

I need to write a 'simple' util to convert from ASCII to EBCDIC? The Ascii is coming from Java, Web and going to an AS400. I've had a google around, can't seem to find a easy solution (maybe coz there isn't one :( ). I was hoping for an opensource…
scottyab
  • 23,621
  • 16
  • 94
  • 105
1 2 3
…
99 100