get_permalink（0）;的结果

Question

I'm new to wordpress and I'm following a tutorial right now but I don't understand wordpresses behaviour. I'm trying to change the title of a sidebar which lists the parentpage and it's childpages, this works fine but I don't understand why $parentID = wp_get_post_parent_id(get_the_ID()); echo get_permalink($parentID); $parentID = wp_get_post_parent_id(get_the_ID()); echo get_permalink($parentID); works even on the parent page, I echoed the result on the parent page and it returns 0 since the parent page doesnt have a parent, so why does this still work? Why does get_permalink(0); get me to the parent page if I press the button?

Answer 1

get_permalink()is the function that gives you the link to the post/page inside the loop you are currently. Since you are not having parent page for the current page get_permalink is not able to get you to the parent page as nothing exist so in this case it will rediret you to the same page.