The ctype_cntrl() is an inbuilt function in PHP which is used to check all the characters in string/text are control characters. Control characters are e.g. line feed, tab, escape.
Syntax:
bool ctype_cntrl ( $str )
Parameters: This function accepts a single parameter $str. It is a mandatory parameter which specifies the string.
Return Value: It returns True if a string contains only control characters and False on failure.
Examples:
Input: neveropen Output: No Explanation: String (neveropen) contains only the alphanumeric characters. Input: \n\t Output: Yes Explanation: String (\n\t) contains only the control character.
Below programs illustrate the ctype_cntrl() function.
Program 1:
php
<?php// PHP program to check if a string has all// control characters$str1 = "neveropen"; if ( ctype_cntrl($str1)) echo "Yes\n"; else echo "No\n";$str2 = "\n\t"; if ( ctype_cntrl($str2)) echo "Yes\n"; else echo "No\n";?> |
Output:
No Yes
Program 2: Implementation of ctype_cntrl() function which takes input of an array of string that contains integers and special Symbol.
php
<?php// PHP program to check if a string has all// control characters $str = array( "Geeks", "Geeks space", "@@##-- /", "\n", "\t \r", "\r\t\n"); // Check the above strings by using// ctype_cntrl() functionforeach ($str as $test) { if (ctype_cntrl($test)) echo "Yes\n"; else echo "No\n"; } ?> |
Output:
No No No Yes No Yes
References: http://php.net/manual/en/function.ctype-cntrl.php
