underscore.js Collections each

Example

The _.each function accepts an array or an object, an iteratee function and an optional context object, the iteratee function is invoked once and in order for each array item The iteratee function provides 3 arguments

item - The current iterated object (or value if an object was passed)
i - The index of the iterated object (or key if an object was passed)
list - A reference to the original array/list (the object that was passed)

Example 1:

_.each(["hello", "underscore"], function(item, i, list) {
    alert(item)
});

The above example will show 2 alerts, the first with the words "hello" and the second for "world".

Example 2:

_.each({one: 1, two: 2, three: 3}, (value, key, object) => 
    console.log(JSON.stringify(object));
);

This example will log a stringified version of the object 3 times.

.each is a terminal operation, and unlike other intermediate functions (map, pluck, values etc..) you don't need to return inside the iteratee function body.