ASCII Encoding
Hello future Hackers,
We have created the next lesson.
This time we talk about ascii encoding.
Again, the challenge is more informative and gives no points.
Happy Challenging!
- gizmore and x
Problem CGX#4
Diese Lektion hat ein interaktives Problem:
72 101 108 108 111 32 71 97 115 116 46 32 83 111 108 117 116 105 111 110 58 32 79 50 87 108 101 108 120 76
Das Problem wird zufällig generiert und ist an Ihre Sitzung gebunden.
Viel Glück!
Das WeChall-Team
# CGX#4: Ascii Encoding
Computers can only work with numbers.
We need a mapping, for converting numbers to written characters, to display text to humans.
The [ASCII](https://en.wikipedia.org/wiki/ASCII)
[encoding](../README.md)
was one of the first encoding to solve this problem.
## ASCII
- 1 byte per character.
- Original 7 bit + 1 bit [checksum]()
- [ASCII Table](https://www.asciitable.com/)
## Other encodings
- C64 Screencode (A=1, B=2, ...)
- 8bit ASCII / extended ASCII
- Win ISO
- Unicode with UTF 8/16/32
## PHP Implementation
- number to letter (chr())
- letter to number (ord())
- string encodings in PHP