返回一个 Observable，该 Observable 镜像第一个源 Observable 发出一个项目。

race<T>(...observables: any[]): Observable<T>

参量

returns

Observable<T>：一个Observable，它镜像第一个 Observable的输出以发出一个项目。

描述

例

订阅第一个开始发射的可观察对象。

import { race, interval } from 'rxjs';
import { mapTo } from 'rxjs/operators';


const obs1 = interval(1000).pipe(mapTo('fast one'));
const obs2 = interval(3000).pipe(mapTo('medium one'));
const obs3 = interval(5000).pipe(mapTo('slow one'));


race(obs3, obs1, obs2)
.subscribe(
  winner => console.log(winner)
);


// result:
// a series of 'fast one'

超载

race(arg: [any]): Observable<A>

returnsObservable<A>

race(arg: [any, any]): Observable<A | B>

race(arg: [any, any, any]): Observable<A | B | C>

race(arg: [any, any, any, any]): Observable<A | B | C | D>

race(arg: [any, any, any, any, any]): Observable<A | B | C | D | E>

race(arg: any[]): Observable<T>

returnsObservable<T>

race(arg: any[]): Observable<{}>

returnsObservable<{}>

race(a: any): Observable<A>

returnsObservable<A>

race(a: any, b: any): Observable<A | B>

race(a: any, b: any, c: any): Observable<A | B | C>

race(a: any, b: any, c: any, d: any): Observable<A | B | C | D>

race(a: any, b: any, c: any, d: any, e: any): Observable<A | B | C | D | E>

race(observables: any[]): Observable<T>

returnsObservable<T>

race(observables: any[]): Observable<{}>

returnsObservable<{}>

race(...observables: any[]): Observable<T>

returnsObservable<T>

race(...observables: any[]): Observable<{}>

returnsObservable<{}>