如何存储rxjs发出的值？

import { Subject } from 'rxjs';

const subject = new Subject();

subject.next('value 1');
subject.next('value 2');

subject.subscribe(value => console.log(value)); // 输出：'value 1', 'value 2'

import { BehaviorSubject } from 'rxjs';

const behaviorSubject = new BehaviorSubject('initial value');

behaviorSubject.next('value 1');
behaviorSubject.next('value 2');

behaviorSubject.subscribe(value => console.log(value)); // 输出：'value 2'

import { ReplaySubject } from 'rxjs';

const replaySubject = new ReplaySubject(2);

replaySubject.next('value 1');
replaySubject.next('value 2');
replaySubject.next('value 3');

replaySubject.subscribe(value => console.log(value)); // 输出：'value 2', 'value 3'