JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/linq.js/2.2.0.2/linq.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/linq.js/2.2.0.2/jquery.linq.js"></script>

JavaScript

var arr =[ {uName:"2015", num1: 100,num2: 10, num3: 0},{uName:"2011", num1: 10, num2: 2, num3: 19},{uName:"2015",num1: 10, num2: 0, num3: 20}];

var expected = $.Enumerable.From(arr).Where(function(x){return x.uName =="2015"}).Select(function(a){ return a.num1}).Sum();
alert(expected);