wordpress, why return $this->get_posts(); returns values?

Question

I was trying to find out how wordpress process each request and returns the result. I found wp() function calls $wp->main() which in turn calls $this->query_posts(); and which calls $wp_the_query->query($this->query_vars) function in query.php file. The query() function calls return $this->get_posts(); and return the result.

My question is didn't see any any variables receiving this returned value so why this function has return, even though the wordpress works if I remove the return from the code. so what is the purpose of this return, (I guess this code saves the contents (posts) to $this->posts variable). btw I am using wp 3.6

Answer 1

I believe this answer may provide what you're looking for:

https://wordpress.stackexchange.com/a/1755

Specifically this image (which I did not create myself):

Answer 2

The use of return is related to php (also used in other languages) not only WordPress. When execution reaches a return statement, the function stops and returns that value without processing any more of the function. A return with no value returns null and If there is no return keyword at the end of a function then, in this case too, a null value get returned.

Using a return statement at the end of a method/function is a good coding practice, it just returns the execution control back to the point, from where it started and it also Prevents Code Injection in PHP include files. Also, check this.