JSFiddle - React, Tailwind, and code Playground

HTML

<script src="//cdnjs.cloudflare.com/ajax/libs/underscore.js/1.5.2/underscore-min.js"></script>

JavaScript

var people = [{firstName : "Thein", city : "ny", qty : 5},{firstName : "Michael", city : "ny", qty : 3}, {firstName : "Bloom", city : "nj", qty : 10} ];

var results = _.map(
    _.where(people, {city : "ny"}), 
    function(person) {
        return { firstName: person.firstName, qty: person.qty };
    }
);
console.log(results);
console.log(JSON.stringify(results));