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What is the async pipe and why is it useful?

Q: What is the async pipe and why is it useful?

**Core concept.** The async pipe subscribes to an **Observable** (or Promise) directly in the template, returns its **latest value**, and — crucially — **automatically unsubscribes** when the component is destroyed. It removes manual subscribe / unsubscribe boilerplate and the memory leaks that come from forgetting to clean up. data$ | async subscribe + render <rect c

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Explain the async pipe.

async-piperxjs

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Consume a stream with no manual subscription

import { Component } from '@angular/core';
import { interval, map } from 'rxjs';

@Component({
  selector: 'app-root',
  standalone: true,
  template: `
    <!-- subscribes + auto-unsubscribes; no ngOnDestroy needed -->
    <p>Seconds: {{ seconds$ | async }}</p>
    <p *ngIf="seconds$ | async as s">unwrapped: {{ s }}</p>
  `,
})
export class AppComponent {
  seconds$ = interval(1000).pipe(map(n => n + 1));
}

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