Replay Subject Example

replay-subject.example.ts

import {ReplaySubject} from 'rxjs/internal/ReplaySubject';

const subject = new ReplaySubject(2 /* buffer size */);

subject.next('a');
subject.next('b');
subject.next('c');

const subscription = subject.subscribe((x: string) => {
  console.log(`Next: ${x}`);
}, (error: Error) => {
  console.log(`Error: ${error}`);
}, () => {
  console.log('Completed');
});

// => Next: b
// => Next: c

subject.next('d');
// => Next: d