Strange “1” displayed at the end of a php print_r ?

Question

Can someone explain me what and why this "1" is displayed at the end of print_r function?

        echo '<pre>'
        echo print_r($validation->getErrorFields());
        echo '</pre>'

Answer 1

Remove the echo before print_r

the print_r is supposed to return true/false which is displayed as 1 with the echo.

So you only need the following.

        echo '<pre>'
        print_r($validation->getErrorFields());
        echo '</pre>'