Returns TRUE if every character is alphabetic or a digit, FALSE otherwise.
Returns TRUE if every character is alphabetic, FALSE otherwise.
Returns TRUE if value is greater than or equal to $min and less than or equal to $max, FALSE otherwise. If $inc is set to FALSE, then the value must be strictly greater than $min and strictly less than $max.
Returns TRUE if it is a valid credit card number format.
Returns TRUE if value is a valid date, FALSE otherwise.
Returns TRUE if every character is a digit, FALSE otherwise.
Returns TRUE if value is a valid email format, FALSE otherwise.
Returns TRUE if value is a valid float value, FALSE otherwise.
Returns TRUE if value is greater than $min, FALSE otherwise.
Returns TRUE if value is a valid hexadecimal format, FALSE otherwise.
Returns TRUE if value is a valid hostname, FALSE otherwise.
Returns TRUE if value is a valid integer value, FALSE otherwise.
Returns TRUE if value is a valid IP format, FALSE otherwise.
Returns TRUE if value is less than $max, FALSE otherwise.
Returns TRUE if value is one of $allowed, FALSE otherwise.
Returns TRUE if value matches $pattern, FALSE otherwise. Uses preg_match() for the matching.