ctype
ctype_alnum
ctype
PHP Manual

# Character Type Functions

## Table of Contents

- ctype_alnum — Check for alphanumeric character(s)
- ctype_alpha — Check for alphabetic character(s)
- ctype_cntrl — Check for control character(s)
- ctype_digit — Check for numeric character(s)
- ctype_graph — Check for any printable character(s) except space
- ctype_lower — Check for lowercase character(s)
- ctype_print — Check for printable character(s)
- ctype_punct — Check for any printable character which is not whitespace or an alphanumeric character
- ctype_space — Check for whitespace character(s)
- ctype_upper — Check for uppercase character(s)
- ctype_xdigit — Check for character(s) representing a hexadecimal digit

ctype
ctype_alnum
ctype
PHP Manual