Underscore.js: Find the most frequently occurring value in an array?

Question

Consider the following simple array:

var foods = ['hotdog', 'hamburger', 'soup', 'sandwich', 'hotdog', 'watermelon', 'hotdog'];

With underscore, is there a function or combination of functions I can use to select the most frequently occurring value (in this case it's hotdog)?

Answer 1

var foods = ['hotdog', 'hamburger', 'soup', 'sandwich', 'hotdog', 'watermelon', 'hotdog'];
var result = _.chain(foods).countBy().pairs().max(_.last).head().value();
console.log(result);

<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.3/underscore.js"></script>

countBy: Sorts a list into groups and returns a count for the number of objects in each group.

pairs: Convert an object into a list of [key, value] pairs.

max: Returns the maximum value in list. If an iterator function is provided, it will be used on each value to generate the criterion by which the value is ranked.

last: Returns the last element of an array

head: Returns the first element of an array

chain: Returns a wrapped object. Calling methods on this object will continue to return wrapped objects until value is used.

value: Extracts the value of a wrapped object.