生命周期

https://www.angular.cn/guide/lifecycle-hooks

export class AppComponent {
  title = 'my-app';
  lists:Array<number> = [1,2,3];
  handleClick():void{
    console.log(this.title)
    this.title = "change"
  }
  // 组件初始化的时候触发 发送http请求
  ngOnInit(){
    console.log("init")
  }
}