ng-repeat: track-by

HTML

<script src="https://code.angularjs.org/1.6.6/angular.js"></script>
<div ng-controller="myController">
  <ul>
    <li ng-repeat="friend in ::friends track by friend.id">{{friend.name}}</li>
  </ul>



</div>

JavaScript

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

myApp.controller('myController', function($scope, $timeout) {



  $scope.friends = [{
    id: 0,
    name: 'BK'
  }, {
    id: 1,
    name: 'BK2'
  }, {
    id: 2,
    name: 'Brian'
  }];
  
  $timeout(function(){
     $scope.friends.push({
    id: 3,
    name: '333'
  });
  },1000);
  
  console.log($scope.friends);

});