NativeScript for Mobile App Development Data Binding and MVVM 2

Question 1

In NativeScript Vue, which directive provides two-way data binding on input elements?

Accepted Answer

v-model

Answer

v-bind

Answer

v-data

Answer

v-sync

Question 2

What is the purpose of the `$` prefix in NativeScript data binding expressions?

Accepted Answer

References the current item in a list binding

Answer

References global variables

Answer

Accesses native platform APIs

Answer

Denotes Angular service injection

Question 3

How do you observe changes to an ObservableArray in NativeScript?

Accepted Answer

Listen to the 'change' event on the ObservableArray instance

Answer

Use array.watch()

Answer

Subscribe to an RxJS observable

Answer

Use array.onUpdate()

Question 4

What happens when you assign a plain JavaScript object (not Observable) as bindingContext?

Accepted Answer

Initial values display but UI won't update when properties change

Answer

The app throws a runtime error

Answer

NativeScript auto-wraps it in Observable

Answer

Binding works exactly the same

Question 5

In NativeScript Angular, how do you emit an event from a child component to its parent?

Accepted Answer

Use @Output() with EventEmitter

Answer

Use @Input() with a callback function

Answer

Call parent.emit() directly

Answer

Use the NativeScript Observable class

Question 6

Which NativeScript class represents an array that notifies listeners of mutations?

Accepted Answer

ObservableArray

Answer

ReactiveArray

Answer

BindableArray

Answer

LiveArray