I need to declare an array

and i need to keep each item added to it should remain for there for ever, even if the page is reloaded, is it possible? var arr=[]; arr.push('id');

like this, but stored item should not be replaced.

You can use cookies in AngularJS to maintain the values. FYI, enter link description herea JSFiddle of this using the $cookieStore, two controllers, a $rootScope, and AngularjS 1.0.6. It's on JSFiddle as https://jsfiddle.net/h2fs0han/ as a base if you're messing around with this...

For more information refer - How to access cookies in AngularJS?

<div ng-app="myApp">
  <div id="lastVal" ng-controller="ShowerCtrl">{{lastVal}}</div>
  <div id="button-holder" ng-controller="CookieCtrl">
    <input type="text" ng-model="strText" />
    <button ng-click="AddItem()">Add Item!</button>
  </div>
</div>

 var myApp = angular.module('myApp', ['ngCookies']);
 myApp.controller('CookieCtrl', function($scope, $rootScope, $cookieStore) {
  $scope.strText = "";

  $scope.AddItem = function() {
    var lastVal = $cookieStore.get('lastValue');
    if ($scope.strText) {
      if (!lastVal) {
        $rootScope.lastVal = new Array(); //Default
        $rootScope.lastVal.push($scope.strText);
      } else {
        var newItem = angular.copy(lastVal);
        newItem.push($scope.strText);
        $rootScope.lastVal = newItem;
      }
      $cookieStore.put('lastValue', $rootScope.lastVal);
    }
  };
});

myApp.controller('ShowerCtrl', function() {});