number of rows

What is the context for this suggestion?

It’s a very frequent necessity to know how many rows where selected. Say, to display Total: 10 replies

It’s built in all php extensions:
https://php.net/manual/en/function.mysql-num-rows.php
https://php.net/manual/en/mysqli-result.num-rows.php
etc.

It was not clear for me where to get this number until I checked a couple of files on github.

I think it’s a good practice