UPDATE and INSERT differences in syntax is an inconvenience
===

I was going through this article today. 

http://vinothbabu.com/2010/05/08/update-and-insert-differences-in-syntax-is-an-inconvenience/

I was not able to understand this part of the code written by the author.

        list($sets,$cols,$values)=escape_arr($sets);

        $insert_sql=”INSERT INTO `avatars` “.implode(’,',$cols).” 
        VALUES(”.implode(’,',$values).”)”;
       
        $update_sql=”UPDATE `avatars` SET “.implode(’,',$sets).”
        WHERE userid=$userid LIMIT 1″;

and finally the conclusion part of the article. 