ASCII stands for American Standard Code for Information Interchange.
ASCII was the first character encoding standard (Charset) used in computing.
This standard was created in the 60‘s and has been fundamental to the field of computing.
ASCII maps the value of 54 to the number 6, 102 to the letter f, and 43 to a plus sign.
6 f +
<p style="font-size:100px;">6 f + </p>
Next, we'll review all 128 numbers and their equivalent ASCII characters.
They are grouped in printable (visible) characters and control (non-visible) characters.
ASCII codes 32-126 are the printable characters (i.e. character that you can see).
These represent letters, numbers, punctuation marks, and some other symbols.
These codes are a very close match to the characters on your keyboard.
This table lists the ASCII printable characters with their corresponding number and description.
| Character | Number | Description |
|---|---|---|
| 32 | space | |
| ! | 33 | exclamation mark |
| " | 34 | quotation mark |
| # | 35 | number sign |
| $ | 36 | dollar sign |
| % | 37 | percent sign |
| & | 38 | ampersand |
| ' | 39 | apostrophe |
| ( | 40 | left parenthesis |
| ) | 41 | right parenthesis |
| * | 42 | asterisk |
| + | 43 | plus sign |
| , | 44 | comma |
| - | 45 | hyphen |
| . | 46 | period |
| / | 47 | slash |
| 0 | 48 | number 0 |
| 1 | 49 | number 1 |
| 2 | 50 | number 2 |
| 3 | 51 | number 3 |
| 4 | 52 | number 4 |
| 5 | 53 | number 5 |
| 6 | 54 | number 6 |
| 7 | 55 | number 7 |
| 8 | 56 | number 8 |
| 9 | 57 | number 9 |
| : | 58 | colon |
| ; | 59 | semicolon |
| < | 60 | less-than |
| = | 61 | equals-to |
| > | 62 | greater-than |
| ? | 63 | question mark |
| @ | 64 | at sign |
| A | 65 | uppercase a |
| B | 66 | uppercase b |
| C | 67 | uppercase c |
| D | 68 | uppercase d |
| E | 69 | uppercase e |
| F | 70 | uppercase f |
| G | 71 | uppercase g |
| H | 72 | uppercase h |
| I | 73 | uppercase i |
| J | 74 | uppercase j |
| K | 75 | uppercase k |
| L | 76 | uppercase l |
| M | 77 | uppercase m |
| N | 78 | uppercase n |
| O | 79 | uppercase o |
| P | 80 | uppercase p |
| Q | 81 | uppercase q |
| R | 82 | uppercase r |
| S | 83 | uppercase s |
| T | 84 | uppercase t |
| U | 85 | uppercase u |
| V | 86 | uppercase v |
| W | 87 | uppercase w |
| X | 88 | uppercase x |
| Y | 89 | uppercase y |
| Z | 90 | uppercase z |
| [ | 91 | left square bracket |
| \ | 92 | backslash |
| ] | 93 | right square bracket |
| ^ | 94 | caret |
| _ | 95 | underscore |
| ` | 96 | grave accent |
| a | 97 | lowercase a |
| b | 98 | lowercase b |
| c | 99 | lowercase c |
| d | 100 | lowercase d |
| e | 101 | lowercase e |
| f | 102 | lowercase f |
| g | 103 | lowercase g |
| h | 104 | lowercase h |
| i | 105 | lowercase i |
| j | 106 | lowercase j |
| k | 107 | lowercase k |
| l | 108 | lowercase l |
| m | 109 | lowercase m |
| n | 110 | lowercase n |
| o | 111 | lowercase o |
| p | 112 | lowercase p |
| q | 113 | lowercase q |
| r | 114 | lowercase r |
| s | 115 | lowercase s |
| t | 116 | lowercase t |
| u | 117 | lowercase u |
| v | 118 | lowercase v |
| w | 119 | lowercase w |
| x | 120 | lowercase x |
| y | 121 | lowercase y |
| z | 122 | lowercase z |
| { | 123 | left curly brace |
| | | 124 | vertical bar |
| } | 125 | right curly brace |
| ~ | 126 | tilde |
The first 32 characters and last character in the ASCII-table are unprintable control codes.
These are used to control peripheral devices, such as printers.
This table lists the ASCII control characters with their corresponding number and description.
| Character | Number | Description |
|---|---|---|
| NUL | 00 | null character |
| SOH | 01 | start of header |
| STX | 02 | start of text |
| ETX | 03 | end of text |
| EOT | 04 | end of transmission |
| ENQ | 05 | enquiry |
| ACK | 06 | acknowledge |
| BEL | 07 | bell (ring) |
| BS | 08 | backspace |
| HT | 09 | horizontal tab |
| LF | 10 | line feed |
| VT | 11 | vertical tab |
| FF | 12 | form feed |
| CR | 13 | carriage return |
| SO | 14 | shift out |
| SI | 15 | shift in |
| DLE | 16 | data link escape |
| DC1 | 17 | device control 1 |
| DC2 | 18 | device control 2 |
| DC3 | 19 | device control 3 |
| DC4 | 20 | device control 4 |
| NAK | 21 | negative acknowledge |
| SYN | 22 | synchronize |
| ETB | 23 | end transmission block |
| CAN | 24 | cancel |
| EM | 25 | end of medium |
| SUB | 26 | substitute |
| ESC | 27 | escape |
| FS | 28 | file separator |
| GS | 29 | group separator |
| RS | 30 | record separator |
| US | 31 | unit separator |
| DEL | 127 | delete (rubout) |
Note: Several of the control characters have their origin in typewriters. For example: Backspace, Linefeed, Carriage Return, Shift In, Shift Out, and Bell. In the early days of computing, printers worked just like typewriters.
