Can’t display multiple terms with get_the_terms

I am trying to display the terms (from a custom taxonomy) of a single post, but I can’t display more than one term. When I try to display all the terms using a foreach loop, it doesn’t display anything.

Here is one of my attempts :

<?php   $  terms = get_the_terms($  post->ID, 'auteur');  if ($  terms && !is_wp_error($  terms)) {     foreach($  terms as $  term) {         echo $  term->name ;     } }           ?> 

It doesn’t display anything. But the same code without foreach loop displays (as expected) one term :

<?php   $  terms = get_the_terms($  post->ID, 'auteur');     echo $  term->name ;      ?> 

I imagine that I’m missing an evident mistake (I’m a beginner), but I can’t understand what is wrong with the foreach loop…

Thank you !