Forgotten functions in PHP

Function

Ctype_alnum--Check for alphanumeric character (s)

Detect if it contains only [a-za-z0-9]

Ctype_alpha--Check for alphabetic character (s)

Detect if it contains only [a-za-z]

Ctype_cntrl--Check for control character (s)

Check whether it is a character control character that contains only the class is "\r\b\t"

Ctype_digit--Check for numeric character (s)

The check is a string containing only numeric characters (0-9)

Ctype_graph--Check for any printable character (s) except spaces

Check whether it is a string that contains only characters that can be printed (except spaces)

Ctype_lower--Check for lowercase character (s)

Check to see if all the characters are in English letters and are all lowercase

Ctype_print--Check for printable character (s)

Check if it is a string that contains only characters that can be printed

CTYPE_PUNCT--Check for any printable character which are not whitespace or a alphanumeric

Check for printable characters that contain only non-numeric/character/space

Ctype_space--Check for whitespace character (s)

Check for characters and spaces that contain only classes such as "\r\b\t"

Ctype_upper--Check for uppercase character (s)

Check that all characters are in English letters and are all uppercase

Ctype_xdigit--Check for character (s) representing a hexadecimal digit

Check if it is a 16-in string and can only include "0123456789abcdef"