import { OnInit } from '@angular/core';
 
export class AppComponent implements OnInit {
  ngOnInit() {
  }
}

<input #newHeroName />
<button (click)="addHero(newHeroName.value); newHeroName.value=''">

    <form (ngSubmit)="onSubmit()" #missionForm="ngForm">
        <input type="text"  class="form-control" required [ngModel]="mission.name" name="name">
        <button type="button" class="btn btn-default" (click)="updateMission(missionForm.form.controls)"><span class="glyphicon glyphicon-open" aria-hidden="true"></span> Update Name</button>
 

let url = `${this.heroesUrl}/${hero.id}`;