How to display the lowest number from multiple fields - PHP?

Question

I have channel entries with around 20 number fields, each containing a price: {price_1}, {price_2}, etc.

I need to display the lowest of these prices in the entry's template but am finding it strangely difficult to do!

My PHP skills are just copy and paste level, and I thought I could just do:

echo min({price_1},{price_2}...)

But some of the price fields may be empty, so I am getting PHP errors.

Any help gratefully received!

Answer 1

How about this?

<?php
$list = array('{price_1}','{price_2}','{price_3}','{price_4}');
$result = array_filter( $list, 'strlen' );
echo min($result); 
?>