jsfiddle-console example
https://github.com/eu81273/jsfiddle-console
HTML
<script src="https://cdn.jsdelivr.net/gh/eu81273/jsfiddle-console/console.js"></script>JavaScript
function moy(){
let somme = 0;
for (let i=0; i < arguments.length; i++) {
somme += arguments[i];
}
let moyenne = (somme / arguments.length) || 0;
console.log(moyenne);
}
moy(12, 8, 13);
moy();