ctype_xdigit(3) [php man page]

CTYPE_XDIGIT(3) 							 1							   CTYPE_XDIGIT(3)

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

SYNOPSIS

       bool ctype_xdigit (string  $text)

DESCRIPTION

	Checks if all of the characters in the provided string, $text, are hexadecimal 'digits'.

PARAMETERS

	      o $text
		- The tested string.

RETURN VALUES

	Returns TRUE if every character in $text is a hexadecimal 'digit', that is a decimal digit or a character from [A-Fa-f] , FALSE otherwise.

EXAMPLES

       Example #1

	      A ctype_xdigit(3) example

	      <?php
	      $strings = array('AB10BC99', 'AR1012', 'ab12bc99');
	      foreach ($strings as $testcase) {
		  if (ctype_xdigit($testcase)) {
		      echo "The string $testcase consists of all hexadecimal digits.
";
		  } else {
		      echo "The string $testcase does not consist of all hexadecimal digits.
";
		  }
	      }
	      ?>

	      The above example will output:

	      The string AB10BC99 consists of all hexadecimal digits.
	      The string AR1012 does not consist of all hexadecimal digits.
	      The string ab12bc99 consists of all hexadecimal digits.

NOTES

       Note

	       If an integer between -128 and 255 inclusive is provided, it is interpreted as the ASCII value of a single character (negative val-
	      ues have 256 added in order to allow characters in the Extended ASCII range). Any other integer is interpreted as a string  contain-
	      ing the decimal digits of the integer.

SEE ALSO

       ctype_digit(3).

PHP Documentation Group 													   CTYPE_XDIGIT(3)