Variables in the $scope object in AngularJS

Within my $scope in angularJS, I am working with two types of variables.

1). $scope.name and $scope.title are linked to input boxes in the UI html code.

2). On the other hand, $scope.sum and $scope.difference are internally used within my JS code. I need these as global variables for accessibility across different functions.

Concern: Will the $scope.$watch function be triggered for the second type of variables? Could these variables potentially have a negative impact on the performance of my page?

javascriptangularjsperformanceangularjs-scope

Answer №1

When it comes to writing expressions in AngularJS, it's important to consider the impact on performance. Avoid using expensive expressions that will be evaluated multiple times as this can significantly slow down your application.

If you notice a performance issue with your application, it's crucial to optimize it accordingly. However, in most cases, keeping things simple and efficient is the way to go without adding unnecessary complexity.

One way to improve performance is by utilizing one-way data binding, indicated by starting the expression with ::. This helps prevent unnecessary recalculation of stable expressions after the initial digest cycle.

Answer №2

Scope variables in AngularJS can be accessed throughout your controller, making them available for use in different functions. To share these variables between controllers, you can utilize services or factories to facilitate communication between scopes.

Answer №3

If you find that those functions are not related to Angular, there is a way to still use them by declaring a global variable in the page and assigning its value to the modal.

app.controller('MainCtrl', function($scope) {
  $scope.name = 'World';
  $scope.globalVariable = "something";
  globalVariable = $scope.globalVariable;
});

var globalVariable;

function externalFunction(){
  alert(globalVariable);
}

Check out this Plunker for example.

If those functions are within another controller, you can utilize a service or factory to share information between controllers. For more information on services and factories in AngularJS, please refer to this link:

AngularJS : Factory and Service?

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