ngRepeat:dupes Error when entering nulls in array

Question

How do I enter successive nulls in a javascript array?

I am having trouble understanding how to enter successive null values in a JS array. This is my working script:

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

myApp.controller("myCtrl", function($scope) {
  $scope.items = [];
  $scope.items[0] = [,,"this doesn't work"];
  $scope.items[0] = [null,"this works"]; 
  $scope.items[1] = [null,,"this works"];
  $scope.items[2] = [null,null,"this doesn't work"];
  $scope.items[3] = [null,,,"this doesn't work"];
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.7.5/angular.min.js"></script>
<body ng-app="myApp">
  <div ng-controller="myCtrl">
    <table>
      <tr ng-repeat="row in items">
        <td ng-repeat="column in row">{{column}}</td>
      </tr>
    </table>
  </div>
</body>

Paste your fiddle as a [stack snippet](https://meta.stackoverflow.com/questions/358992/ive-been-told-to-create-a-runnable-example-with-stack-snippets-how-do-i-do) — Klaycon, Dec 10 '19 at 20:04
@epascarello Yes, it remains blank in the rows that don't work. — JcoOnline, Dec 10 '19 at 20:10
`$scope.items[2]` is how you would "enter successive nulls in a javascript [sic] array". — Heretic Monkey, Dec 10 '19 at 20:12
Notice how every example that works *has no repeats* and every example that doesn't work repeats null or undefined. See the linked dupe target for info on resolving. Problem is incorrect use of `ng-repeat`. — Klaycon, Dec 10 '19 at 20:14

score 1 · Answer 1 · answered Dec 10 '19 at 20:22

1

Problem appears to be with how you are outtputting the values in your angular ng-repeat. Alter the code to use track by to deal with duplicated values.

<tr ng-repeat="tr in items">
    <td ng-repeat="td in tr track by $index">{{td}}</td>
</tr>

answered Dec 10 '19 at 20:22

epascarello

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Excellent suggestion, thank you. – JcoOnline Dec 10 '19 at 20:26

ngRepeat:dupes Error when entering nulls in array

How do I enter successive nulls in a javascript array?

1 Answers1