Calculate all custom field values in the post loop

Question

I have a custom post type named 'ordered_food' and the custom field named 'price', Alhough I can print out all the values, I don't know how to plus and calculate the total price. Because it's already in the wordpress custom post type loop.

/* something like this */
$total_amount = $price_custom_field1 + $price_custom_field2 + $price_custom_field3; 

Answer 1

Try this:

//loop start

    $total_amount = get_post_meta($post->ID, 'custom_field1', true);
    $total_amount += get_post_meta($post->ID, 'custom_field2', true);
    $total_amount += get_post_meta($post->ID, 'custom_field3', true);

//loop end  

    echo 'Total: '.$total_amount;