源代码:
import { Component, OnInit } from '@angular/core'; import { JerrySandBoxService } from './jerrySandBoxService'; import { GreetingService } from './greeting.service'; import { fromEvent } from 'rxjs'; @Component({ selector: 'app-root', templateUrl: './app.component.html', styleUrls: ['./app.component.scss'] }) export class AppComponent implements OnInit { title = 'sandbox'; constructor(private jerryService: JerrySandBoxService, private englishGreet: GreetingService){ // this.jerryService.print(); this.jerryService.print2(); console.log(this.englishGreet.greet('Jerry')); } ngOnInit(): void { const button = document.querySelector('button'); fromEvent(button, 'click').subscribe(() => { console.log('I am Clicked!'); }); } jerryTest(){ console.log('Hello'); } }
在html里定义一个button:
scan 操作符的工作原理与数组的 reduce 类似。它需要一个暴露给回调函数当参数的初始值。每次回调函数运行后的返回值会作为下次回调函数运行时的参数。