[test] test values of string

"0123456789"

decimal symbols
isdigit()


"0123456789abcdef"
"0123456789ABCDEF"

hexadecimal symbols
isxdigit()


"abcdefghijklmnopqrstuvwxyz"
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"

alphabet symbols
isalpha()
isupper() / islower()


"+-*/"

arithmetic operators


ref:

http://en.wikipedia.org/wiki/Addition (+)
http://en.wikipedia.org/wiki/Subtraction (-)
http://en.wikipedia.org/wiki/Multiplication (*)
http://en.wikipedia.org/wiki/Division (/)