ASCII
With American Standard Code for Information Interchange (ASCII), we can represent a character using a code that associates 7 bits binary digits.
A = 1000001 = 65 (decimal)
B = 1000010 = 66
…
a = 1100001
b = 1100010
space = 0100000
etc…
Keyboard symbols in ASCII
| symbol | name | ASCII code (decimal) |
|---|---|---|
| ! | Exclamation mark | 33 |
| ” | Double quotes | 34 |
| # | Hashtag | 35 |
| $ | Dollar | 36 |
| % | Per cent sign | 37 |
| & | Ampersand | 38 |
| ` | Single quote | 39 |
The maximum code value ASCII can represent is 127(7 bits) or 1111111, that is 128 (0-127) characters can be represented. However, 128 characters are far from enough to represent other languages with their characters (e.g. Chinese characters), therefore we need a new encoding standard (i.e. Unicode).
Unicode
Unicode using 32bits (4 bytes) for a character representation, which could theoretically represent 4 billion characters. Currently there are over 140,000 characters represented in unicode that cover more than 150 languages, including emojis.
Operating_systemINFO1112Character_representationUnicodeASCII