如何在RXJS订阅中运行多个条件

import { of } from 'rxjs';
import { mergeMap } from 'rxjs/operators';

const source = of(1, 2, 3);

source.pipe(
  mergeMap((value) => {
    // 添加多个条件
    if (value === 1) {
      return of('Condition 1');
    } else if (value === 2) {
      return of('Condition 2');
    } else if (value === 3) {
      return of('Condition 3');
    }
  })
).subscribe((result) => {
  console.log(result);
});

import { of, forkJoin } from 'rxjs';

const condition1$ = of('Condition 1');
const condition2$ = of('Condition 2');
const condition3$ = of('Condition 3');

forkJoin([condition1$, condition2$, condition3$]).subscribe(([result1, result2, result3]) => {
  console.log(result1);
  console.log(result2);
  console.log(result3);
});