Sometimes it is useful to display all methods name given a reference to object. This can be used to debug and understand wordpress or any other existing code. Here is code snippet for wordpress $query object.
$class = get_class ($query);
error_log("=====class=$class");
$methods = get_class_methods($class);
error_log("=====methods=" . print_r($methods, True));
Now visit any web page which will cause above code to execute and look for log entries in php error log in /var/log/php_errors.log. The log location may be different on your system. Here is the outcome for above code inside a wordpress code:
[16-Nov-2015 07:35:09 UTC] =====class=WP_Query
[16-Nov-2015 07:35:09 UTC] =====methods=Array
(
[0] => init
[1] => parse_query_vars
[2] => fill_query_vars
[3] => parse_query
[4] => parse_tax_query
[5] => set_404
[6] => get
[7] => set
[8] => get_posts
[9] => next_post
[10] => the_post
[11] => have_posts
[12] => rewind_posts
[13] => next_comment
[14] => the_comment
[15] => have_comments
[16] => rewind_comments
[17] => query
[18] => get_queried_object
[19] => get_queried_object_id
[20] => __construct
[21] => __get
[22] => __isset
[23] => __call
[24] => is_archive
[25] => is_post_type_archive
[26] => is_attachment
[27] => is_author
[28] => is_category
[29] => is_tag
[30] => is_tax
[31] => is_comments_popup
[32] => is_date
[33] => is_day
[34] => is_feed
[35] => is_comment_feed
[36] => is_front_page
[37] => is_home
[38] => is_month
[39] => is_page
[40] => is_paged
[41] => is_preview
[42] => is_robots
[43] => is_search
[44] => is_single
[45] => is_singular
[46] => is_time
[47] => is_trackback
[48] => is_year
[49] => is_404
[50] => is_main_query
[51] => setup_postdata
[52] => reset_postdata
)
