Passing data between controllers in Angular JS?

how do pass this clicked products from first controller to second?

On click you can call method that invokes broadcast:

$rootScope.$broadcast('SOME_TAG', 'your value');

and the second controller will listen on this tag like:

$scope.$on('SOME_TAG', function(response) {
      // ....
})

Since we can't inject $scope into services, there is nothing like a singleton $scope.

But we can inject $rootScope. So if you store value into the Service, you can run $rootScope.$broadcast('SOME_TAG', 'your value'); in the Service body. (See @Charx description about services)

app.service('productService',  function($rootScope) {/*....*/}

Please check good article about $broadcast, $emit

Solution without creating Service, using $rootScope:

To share properties across app Controllers you can use Angular $rootScope. This is another option to share data, putting it so that people know about it.

The preferred way to share some functionality across Controllers is Services, to read or change a global property you can use $rootscope.

var app = angular.module('mymodule',[]);
app.controller('Ctrl1', ['$scope','$rootScope',
  function($scope, $rootScope) {
    $rootScope.showBanner = true;
}]);

app.controller('Ctrl2', ['$scope','$rootScope',
  function($scope, $rootScope) {
    $rootScope.showBanner = false;
}]);

Using $rootScope in a template (Access properties with $root):

<div ng-controller="Ctrl1">
    <div class="banner" ng-show="$root.showBanner"> </div>
</div>

From the description, seems as though you should be using a service. Check out http://egghead.io/lessons/angularjs-sharing-data-between-controllers and AngularJS Service Passing Data Between Controllers to see some examples.

You could define your product service (as a factory) as such:

app.factory('productService', function() {
  var productList = [];

  var addProduct = function(newObj) {
      productList.push(newObj);
  };

  var getProducts = function(){
      return productList;
  };

  return {
    addProduct: addProduct,
    getProducts: getProducts
  };

});

Dependency inject the service into both controllers.

In your ProductController, define some action that adds the selected object to the array:

app.controller('ProductController', function($scope, productService) {
    $scope.callToAddToProductList = function(currObj){
        productService.addProduct(currObj);
    };
});

In your CartController, get the products from the service:

app.controller('CartController', function($scope, productService) {
    $scope.products = productService.getProducts();
});