php man page for ctype_alpha

CTYPE_ALPHA(3)								 1							    CTYPE_ALPHA(3)

ctype_alpha - Check for alphabetic character(s)

SYNOPSIS
       bool ctype_alpha (string  $text)

DESCRIPTION
	Checks	if  all  of  the  characters in the provided string, $text, are alphabetic. In the standard C locale letters are just [A-Za-z] and
       ctype_alpha(3) is equivalent to (ctype_upper($text) || ctype_lower($text)) if $text is just a single character, but  other  languages  have
       letters that are considered neither upper nor lower case.

PARAMETERS
	      o $text
		- The tested string.

RETURN VALUES
	Returns TRUE if every character in $text is a letter from the current locale, FALSE otherwise.

EXAMPLES
       Example #1

	      A ctype_alpha(3) example (using the default locale)

	      <?php
	      $strings = array('KjgWZC', 'arf12');
	      foreach ($strings as $testcase) {
		  if (ctype_alpha($testcase)) {
		      echo "The string $testcase consists of all letters.
";
		  } else {
		      echo "The string $testcase does not consist of all letters.
";
		  }
	      }
	      ?>

	      The above example will output:

	      The string KjgWZC consists of all letters.
	      The string arf12 does not consist of all letters.

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_upper(3), ctype_lower(3), setlocale(3).

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