Interview Questions
1. What is the purpose of AsyncPipe in Angular?
The AsyncPipe is used to subscribe to an observable or promise and return the latest value it has emitted. When a new value is emitted, the pipe marks the component that has been checked for changes.
See the following example where a time observable continuously updates the view for every 2 seconds with the current time.
Example:
@Component({
selector: 'async-observable-pipe',
template: `<div><code>observable|async</code>:
Time: {{ time | async }}</div>`
})
export class AsyncObservablePipeComponent {
time = new Observable(observer =>
setInterval(() => observer.next(new Date().toString()), 2000)
);
}
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