Table of Contents
What is an Angular watch?
When you create a data binding from somewhere in your view to a variable on the $scope object, AngularJS creates a “watch” internally. A watch means that AngularJS watches changes in the variable on the $scope object. The framework is “watching” the variable.
What is the replacement of the controller and scope in angular 2?
The controllers and $scope in Angular 1 have been replaced with “Components” in Angular 2. Hence we can say that it is a component-based framework, which uses zone. js to detect changes.
Why was angular 2 rewritten?
It was rewritten to allow for a decoupling of the framework from the DOM, enabling use of multiple renderers; Microsoft’s TypeScript, a typed superset of JavaScript, was used in the rewrite.
Which of the following logging service angular 2.0 contains to measure where time is spent in your application?
| Q. | Angular 2.0 contains a logging service called . . . . . which is very usefulfeature measuring where time is spent in your application. |
|---|---|
| B. | logging.js |
| C. | diary.js |
| D. | none of above |
| Answer» c. diary.js |
What is $rootScope in Angularjs?
Root Scope All applications have a $rootScope which is the scope created on the HTML element that contains the ng-app directive. The rootScope is available in the entire application. If a variable has the same name in both the current scope and in the rootScope, the application uses the one in the current scope.
What is change detection in Angular?
Change Detection is the backbone of the Angular framework, and each component has its own change detector. Angular can detect when data changes in the component, and can re-render the view to display the updated data. Angular makes sure that data in the component and the view are always in sync with each other.
What is scope hierarchy in Angular?
The $scope object used by views in AngularJS are organized into a hierarchy. Each view has its own $scope (which is a child of the root scope), so whatever variables one view controller sets on its $scope variable, those variables are invisible to other controllers.
What are the new features of angular 2?
Some Important Features of Angular 2 are:
- Modern, faster, and highly scalable framework.
- Equally useful framework for web, mobile, and desktop apps.
- Web components based architecture.
- Supports Hierarchical Dependency Injection.
What is the equivalent of watching for variable changes in AngularJS?
In AngularJS you were able to specify watchers to observe changes in scope variables using the $watch function of the $scope. What is the equivalent of watching for variable changes (in, for example, component variables) in Angular? In Angular 2, change detection is automatic… $scope.$watch () and $scope.$digest () R.I.P.
What are the $watches() in angular?
These change detectors are created when Angular creates components. They keep track of the state of all of your bindings, for dirty checking. These are, in a sense, similar to the automatic $watches () that Angular 1 would set up for { {}} template bindings.
What’s new in Angular 2 2 0?
47 Angular 2.0is using thisinstead of $scope. One of the major changes coming in 2.0 is the death of the controller, and a new emphasis on components.
What is a changedetector in angular?
There is one such change detector (class) per component/directive. (You can get access to this object by injecting ChangeDetectorRef .) These change detectors are created when Angular creates components. They keep track of the state of all of your bindings, for dirty checking.