JSFiddle - React, Tailwind, and code Playground

HTML

<div id="app" ng-app="myApp" >
    
<div ng-controller='myCtrl'>

    <div ng-class="{'newclass':(tarray.indexOf(2)>-1)}">Yay
   </div>
</div>

JavaScript

var myApp = angular.module('myApp', []);

myApp.controller('myCtrl', function ($scope) {
    $scope.tarray=[1,2,5];

});