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What does interval() do?

interval() in RxJS creates an Observable that periodically emits numbers with a time delay.


Example:

ts
import { interval } from 'rxjs'; interval(1000).subscribe(x => console.log(x));

This outputs:

javascript
0 1 2 3 ...and so on, every second

Each number is a "tick". It starts at 0 and increases by 1.


Parameter:

  • interval(1000) means every 1000ms (1 second)
  • if you write interval(500), it will tick twice a second

Where it's used:

  • Timers
  • Animations
  • Status checks
  • Periodic data loading

Conclusion:

interval() creates an infinite stream of numbers, starting from 0 and continuing every N milliseconds. Very handy when you need to do something regularly over time.

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