Character Encodings

Transcript

1. Counting Systems Why your Emojis Work on Twitter, but not Tinder
3. The Beginning
4. Unary Numbers • I • II • IIIII • IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII
5. Romans
6. Romans
8. Why don’t we just use unique symbols? • Glyph - any symbol used to represent some value • 1 2 3 4 5 6 7 8 9
10. Modern Counting Systems
11. Decimal • Latin decimus - tenth • 0 1 2 3 4 5 6 7 8 9
12. Positional Notation • way of encoding numbers • each position related to the next by a constant multiplier called the base or radix • base 10
18. Binary • Latin binarius - consisting of two • Base 2
22. Bits and Bytes • Bit - The basic unit of information in computing • i.e. 0 • Byte - unit of digital information consisting of 8 bits • i.e. 1000 0101
24. Hexadecimal • Greek hex - sixth; decimal - tenth • base 16
25. base 16 • 0 1 2 3 4 5 6 7 8 9 A B C D E F
26. • 10 = ? • A • 255 = ? • FF
27. So…what about the computers?
28. ASCII • American Standard Code for Information Interchange • 0-127 characters • 7 bits
30. Unicode • computing industry standard for encoding, representation, and text expressed in most of the world’s writing systems • code points in range 0 -10FFFF
32. Hexadecimal Code Points • U+0061 = 97 = a • U+005A = 122 = z • U+1F4A9 = 128169 = ?
33. UTF-8 • variable-width character encoding • capable of encoding all unicode characters • backwards compatible with ASCII
34. • http://play.golang.org/p/PvVhLj_5kM • http://play.golang.org/p/pO97Yf5w-z
35. Thanks • @askwheeler • github.com/alexwheeler • alexwheeler.io