Replay Subject - RXJS

In this tutorial, we will learn about the Replay Subject of RXJS.

Replay Subject

ReplySubject stores multiple old Emittedvalue according to the specified time

For example we can store the last 3 value for the last 3 min we can do that

import { ReplaySubject} from 'rxjs';

mySubject = new ReplaySubject<string>(3, 5000);

this.mySubject .next(1);
this.mySubject .next(2);
this.mySubject .next(3);
this.mySubject .next(4);


mySubject.subscribe(res => {
  console.log('1st sub:', res);
});

setTimeout(() => {
mySubject.subscribe(res => {
  console.log('2nd sub:', res);
});

},1000)

Above will give output:

1st sub: 1
1st sub: 2
1st sub: 3
1st sub: 4
2nd sub: 3
2nd sub: 4

The Above example will store the last three emissions for 5 seconds as we are subscribing seconds subscriber after one second it will show the last two values