一 of操作符
从一个数组、类数组对象、Promise、迭代器对象或者类 Observable 对象创建一个 Observable.
import { Component, OnInit } from '@angular/core'; import { of } from 'rxjs/observable/of'; import { Observable } from 'rxjs/Observable'; @Component({ selector: 'app-create', templateUrl: './create.component.html', styleUrls: ['./create.component.css'] }) export class CreateComponent implements OnInit { constructor() { } ngOnInit() { // 从数组创建 const arr = ['red', 'yellow', 'blue']; const colors: Observable<string[]> = of(arr); colors.subscribe((colorsArr: string[]) => { console.log(colorsArr); }); // 从迭代器对象创建 const map: Map<string, any> = new Map(); map.set('fruit', 'orange'); of(map).subscribe( (fruitsMap: Map<string, any>) => { console.log(fruitsMap); } ); } }