Character Tests
Character Tests
Section titled “Character Tests”isalpha(<string>)
isalnum(<string>)
isdigit(<string>)
islower(<string>)
isupper(<string>)
ispunct(<string>)
isspace(<string>)
isxdigit(<string>)
Each returns 1 when the first character of <string> is of one kind, and 0 otherwise or when <string> is empty. Only ASCII characters count:
- isalpha(): a letter.
- isalnum(): a letter or a digit.
- isdigit(): a digit, 0 to 9.
- islower() and isupper(): a lower-case or capital letter.
- ispunct(): a printable character that is not a letter, a digit or a space.
- isspace(): a space, tab, line break, vertical tab, form feed or carriage return.
- isxdigit(): a hexadecimal digit, 0 to 9 or a to f in either case.
These functions come from RhostMUSH.
> think isalpha(a123) [isdigit(a123)] [isxdigit(f00)] [ispunct(!)]1 0 1 1::: seealso