PHP - Arrays

1. Array
2. Associative Array
3. Array in key/value pairs
4. Array in key/value pairs using each
5. sort
6. asort
7. ksort
8. Special Arrays
9. The _SERVER variable
10. A simple form
11. A simple calculator
12. If statement
13. for loop
14. Exercise: improve the calculator
15. Exercise: keep values in the fields