Add _.pickUp function to underscore object. This function (like _.pick function) returns a copy of the array, filtered to only have values for the whitelisted values (or array of values). For example: _.pickUp(['yes', 'no', 'yep', 'nope'], true, false, true, false) returns ['yes', 'yep'] Allow to pass second parameter as an array of values: _.pi…

underscore-pickup-mixin.js

(function () {
	'use strict';
	_.mixin({
		pickUp: function () {
			var args = Array.prototype.slice.call(arguments),
				array = args.shift(),
				result = [];

			if (args.length === 1 && _.isArray(args[0])) {
				args = args.shift();
			}

			_.each(args, function (value, key) {
				if (value) {
					result.push(array[key]);
				}
			});

			return result;
		}
	});
}());