Angular Dump 3e1r2y

1) Below is a constructor definition in Angular: constructor(public name:string, public age?:number); You have written a class in Angular which contains several HTTP client requests. Now, if you get an HTTP error, you wish to catch the exception and print it on the console. Which of the following code snippet performs the same operation? ANS: .map((res) => { return res as Object }) .catch((e) => console.log('Error', e)) .toPromise(); 2) You are writing a unit test in Jasmine for your Angular class. You access the Angular element using the following code: fixture.debugElement.query(By.css('h1')); Appending an ID to a youtube video URL is considered safe in Angular. Which of the following code snippet can be used to make Angular trust a video URL? ANS: updateVideoUrl(id: string) { this.dangerousVideoUrl = 'https://www.youtube.com/embed/' + id; this.videoUrl = this.sanitizer.bySecurityTrustResourceUrl(this.dangerousVideoUrl); } 3) You are working on an Angular 2 project where you wish to inject a window object into one of the constructors in your code. Which of the following is the correct way to do this? ANS: constructor(@Inject("windowObject") window: Window}) 4) In Angular 2, we need to include 1) We can split our application to feature modules and load them on-demand 2) Decrease startup time ANS: None of the mentioned 7) In a scenario of changing the background color of an element dynamically, which of the following attribute directives can be used? Note: There can be multiple correct answers to this question. Options: Ng-switch Ng-style Ng-class ANS: All 8)In the context of XSS, which of the given HTML elements will be treated as untrusted by default? Note: There can be multiple correct answers to this question. ANS: 9) In Angular 2, below is this.http points to the angular HTTP service. this.http.get(url) Considering the standard practice, from which section of a component would you use service to fetch data from the server? ANS: ngOnInit lifecycle hook 10) Module A has a public component (X), directive (Y) and pipe(Z). Module A is imported in module B. Which among X, Y & Z can be used in module B’s component’s template? ANS: X, Y & Z 11) Given that there are 3 modules A, B & C imported into the root module. In a session, a navigates through routes only attached to module A. Comment on which all modules will be loaded in this session. ANS: Module A, B, C & root 12)Given 2 route definitions. Which of the following component will be displayed for the url/messages/1? [{

path: 'messages', component: C1

}, {

path: 'messages/:id',

component: C2 }] For the path /messages/:id, how would you obtain the value of id parameter inside the component? ANS: Import ActivatedRoute service as X. X.params.subscribe 13) Given the interpolation expression performed on a website to display a set of products to the customer. {{ let item of items | filter: text | orderBy: name }} ANS: Chained pipe 14) A common way of applying filters is to pipe it along with the data in the interpolation expression ( {{ data | filter }} ). What is the significance of the pipe here? ANS: Pipe streams the output of the left-hand side as the input to the right-hand side. 15) While fetching a response from the server, services generally adopt the mechanism of an emitting event. Which of the following emits a single cancellable event? ANS: Observables 16) 1. Add Injectable decorator 2. Create a myservice.service.ts 3. Export the service class 4. Import the injectable Sort the above steps in chronological order. ANS: 2 4 1 3 17) A component implements the OnInit interface. Which of ngOnInit() and the component constructor will be called first? ANS: constructor 18)Which of the following metadata properties are not found in @Component decorator? ANS: import 19) Which of the following directives when set to false does not allow further execution in child HTML elements? ANS: ngIf 20)