Angular: How to get each symbol from array n times in random order?

Question

I have the array with symbols A-E I need to output each symbol in ng-repeat, but array should be in random order and each symbol should be displayed n times (for example 4 times)

$scope.symbols = [a, b, c, d, e]; I need to output this array for example like this [a, b, c, d, b, e, c, d, e, a, a, b, c, d, b, e, c, d, e, a] Each symbol must be shown 4 times, and all symbols must be shown randomly. — MikeDiam, Jul 13 '16 at 16:36
Create array containing each symbols `BASE = [a...e]`, create new array add N times all elements of BASE to that copy. Shuffle the last array and return it to ng-repeat. How to shuffle: http://stackoverflow.com/questions/6274339/how-can-i-shuffle-an-array-in-javascript — csharpfolk, Jul 13 '16 at 16:51

score 1 · Accepted Answer · answered Jul 13 '16 at 18:02

You can use the Array.prototype.sort() method to shuffle your array.

I created a function that you can pass as parameters the initial array and the times that you want to sort it, as below:

(function() {
  "use strict";
  angular.module('app', [])
    .controller('mainCtrl', function($scope) {
      function randomize(array, times) {
        var temp = [];
        for (var i = 0; i < times; i++) {
          array.sort(function() {
            return .5 - Math.random();
          });
          temp = temp.concat(array);
        }
        return temp;
      }

      $scope.symbols = randomize(['a', 'b', 'c', 'd', 'e'], 4);
    });
})();

<!DOCTYPE html>
<html ng-app="app">

<head>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.5.7/angular.min.js"></script>
</head>

<body ng-controller="mainCtrl">
  Words:
  <div ng-repeat="symbol in symbols track by $index" ng-bind="symbol">
  </div>
</body>

</html>

score 0 · Answer 2 · answered Jul 13 '16 at 17:27

You ll probably need two functions, one to shuffle the symbols and other to set a array 'N' times with shuffling.

To Set it :

var num = 5; // 'N' time shuffling.

function setArray() {
   for(var i = 0; i < num; i++) {
     $scope.symbols = $scope.symbols.concat(shuffle());
   }
 }

setArray();

here shuffle() is another function to select a random order of the symbols.

See DEMO here.

score 0 · Answer 3 · answered Jul 13 '16 at 17:42

OK, since the other suggestions were just so complicated, I'll build out from my comment.

var result = [];
for (var i=0; i<4; i++) {
    for (var j=0; j<yourArray.length; j++) {
        var newIndex = Math.floor(Math.random() * result.length);
        result[newIndex] = yourArray[i];
    }
}

You could probably even make a filter from this.

Angular: How to get each symbol from array n times in random order?

3 Answers3