Branka Branka - 4 months ago 5x
Javascript Question

How to compare two arrays to see how many same elements they have?

I have two arrays, one is answers, and second one is correctAnswers and i need to see how many elements in answers are the same as in array of correctAnswers and to get percent how many "answers" are "correct". How do i do that?
The arrays are something like this:

answers = ["Hrtkovci","Lepenica","Dec"]

correctAnswers = ["Lepenica","Dec","Leskovac"]

And i dont know if it matters but everything is with angular.


You can use angular.forEach to go through each item in both arrays and check if they are equal.

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

    $scope.answers = ["Hrtkovci", "Lepenica", "Dec"];
    $scope.correctAnswers = ["Lepenica", "Dec", "Leskovac"];

    $scope.compareArrays = function (arr1, arr2) {
        var inBoth = [];
        angular.forEach(arr1, function (a1) {
            angular.forEach(arr2, function (a2) {
                if (a1 == a2) {
        //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);


Edit: Sorry, didn't see you wanted correct answers and percentage. Updated Fiddle.