Top 20 pizzas

olo.js

//require underscore & jquery
var pizzas={};

$.ajax({
    type: 'GET',
    url: 'http://files.olo.com/pizzas.json',
    async: false,
    contentType: "application/json",
    dataType: 'json',
    success: function (data) {
        pizzas=data;
    },
    error: function (e) {
        alert('error');
        console.log(e);

    }
});

    
var sortedByTimesOrdered=_.chain(pizzas)
  .map(function(pizza) { return pizza.toppings; })
  .countBy(function(toppings){ return toppings;})
  .map(function(value,key){return {toppings: key.split(","), timesOrdered: value};  } )
  .sortBy('timesOrdered')                
  .value().reverse();

console.log(JSON.stringify(sortedByTimesOrdered.slice(0,20)));