get_the_author( string $deprecated = '' )

function get_the_author($deprecated = '') {
	global $authordata;

	if ( !empty( $deprecated ) )
		_deprecated_argument( __FUNCTION__, 'WP-2.1.0' );

	/**
	 * Filters the display name of the current post's author.
	 *
	 * @since WP-2.9.0
	 *
	 * @param string $authordata->display_name The author's display name.
	 */
	return apply_filters('the_author', is_object($authordata) ? $authordata->display_name : null);
}