Several forgotten PHP string processing functions

The use of PHP string processing functions can greatly reduce the burden of programming, some of the PHP language has been forgotten some but very powerful PHP string processing functions, this article is not a single example to illustrate, we are interested in the words can be tested on their own.

(PHP 4 >= 4.0.4, PHP 5)

Function prototype bool Ctype_alnum (string text)
Ctype_alnum--Check for alphanumeric character (s)
Detects if it contains only [a-za-z0-9]

Function prototype bool Ctype_alpha (string text)
Ctype_alpha--Check for alphabetic character (s)
Detects if it contains only [a-za-z]

Ctype_cntrl--Check for control character (s)
Check if it is a character control character that contains only the class "\r\b\t"

Ctype_digit--Check for numeric character (s)
Check time is a string containing only numeric characters (0-9)

Ctype_graph-Check for any printable character (s) except space
Check if it is a string that contains only characters that can be printed (except for spaces)

Ctype_lower--Check for lowercase character (s)
Check if all characters are English letters and are lowercase

Ctype_print--Check for printable character (s)
Check if it is a string containing only the characters that can be printed

CTYPE_PUNCT--Check for any printable character which are not whitespace or an alphanumeric character
Check if it is a printable character that contains only non-digits/characters/spaces

Ctype_space--Check for whitespace character (s)
Check if it is a character and space that contains only classes such as "\r\b\t"

Ctype_upper--Check for uppercase character (s)
Check if 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 binary string and can only include "0123456789abcdef"

The above is a few of the PHP language forgotten some but very powerful PHP string processing functions, I hope to be helpful.