By default, Angular runs in the development mode and builds a debugging elements tree--a tree, which has almost the same structure as a rendered DOM, but with objects of type DebugElement. Whenever ng.probe(element) is invoked in the browser console, a corresponding debug element is returned. The DebugElement class extends DebugNode (https://angular.io/docs/ts/latest/api/core/index/DebugNode-class.html).
In the production mode, no debugging elements tree is available and you cannot debug an Angular application with ng.probe. The production mode is enabled with enableProdMode(), which is a function from Angular's package, @angular/core.
Let's see how to use public methods of the exposed DebugElement. First of all, we need to select a DOM element in DevTools. This keeps a reference to the selected DOM node in the variable $0, which can then be accessed from the console. In the CRUD application, we will select the Add button, as shown in the following screenshot...
