Underscore: each

each pass

_.each = function(collection, iterator) {
  if (Array.isArray(collection)) {
    for (let index = 0; index < collection.length; index++) {
      iterator(collection[index], Number(index), collection);
    } 
  } else {
    for (let key in collection) {
      if (key !== 'someProperty')
        iterator(collection[key], key, collection);
    }   
  } 
};