JSFiddle - React, Tailwind, and code Playground

HTML

<div ng-app="app" ng-controller="MyController"></div>

JavaScript

var app = angular.module('app', [])
app.controller('MyController', function ($scope) {

    $scope.answers = ["a","c","b"];
    $scope.correctAnswers = ["b", "a" , "d"];
    $scope.compareArrays = function (arr1, arr2) {
        var inBoth = [];
        angular.forEach(arr1, function (a1) {
            angular.forEach(arr2, function (a2) {
                if (a1 == a2) {
                    inBoth.push(a1);
                }
            });
        });
        //return inBoth;
        var correct = 'You got ' + inBoth.length + '/' + arr2.length + ' answers!';
        var percentage = 'Correct: ' + ((inBoth.length / arr2.length) * 100).toFixed(2) + '%';
        alert(correct + '\n' + percentage);
    };

    $scope.compareArrays($scope.answers, $scope.correctAnswers);

});