The simplest way is a for loop:
for (let i = 0; i < foo.length; i++) {
// Do stuff
}
This is the best solution, as pointed out here it's bad practice to use array methods or convert a NodeList to an array - use a different variable if you need to, but a for loop is all you need to loop over a NodeList. (Thanks Heretic Monkey for pointing this out to me).
If you want to use array methods like forEach, map, etc., it's best convert to an array first - this is incredibly simple with spreading:
[...foo].forEach(e /* Do stuff */);
If you want to specifically use map, use Array.from as the second argument is the callback to be applied to map.
Array.from(foo, e => /* .map callback */);
And in older environments:
Array.prototype.slice.call(foo).forEach(e => /* Do stuff */);
(I know that you can use array methods on a NodeList, but it's easier if you stick to using one data type.)
