import { Component , Input , ChangeDetectorRef } from '@angular/core' ; @ Component ( { selector : 'app-hello-world' , template : `
    <mat-card> Hello, {{ person?.name }} </mat-card>
  ` } ) export class HelloWorldComponent { @ Input ( ) person : { name : string ; } ; constructor ( private cd ) { console . log ( 'instantiated' ) ; } ngOnInit ( ) { console . log ( 'initialized' ) ; } }