Checks if a string is ASCII.

The negative regex is faster for non-ASCII strings, as it allows the search to finish as soon as it encounters a non-ASCII character.

$string string Required

String to check.

bool True if ASCII, false if not.

File: wp-includes/class-wpdb.php. View all references

protected function check_ascii( $string ) {
	if ( function_exists( 'mb_check_encoding' ) ) {
		if ( mb_check_encoding( $string, 'ASCII' ) ) {
			return true;
		}
	} elseif ( ! preg_match( '/[^\x00-\x7F]/', $string ) ) {
		return true;
	}

	return false;
}