Underscore.js - Add attributes to each object of an array

add-attributes.js

/**
 * Add attributes to each object of an array.
 * 
 * @param {array} foo - Array of objects where we will add the attibutes
 * @param {function} iterator
 */ 
_.each(foo, function(element, index) {
	_.extend(element, {field1: index}, {field2: 'bar', field3: 'baz'});
});