Apply default style and onClick change style of a button -Angular 4

Question

I have one button, i want to apply a default style of a button and when user click on a button change a button style color to red and background-color to white. Blow is my .css and component.

.btn-default {
  color: white;
  background-color: blue;

}

.btn-change {
  color: Red;
  background-color: white;
}

Component.ts

import { Component } from '@angular/core';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent {

  bntStyle: string;
  AppComponent() {

   this. bntStyle = 'btn-default';
  }
  submit() {
    this.bntStyle = 'btn-change';

  }

.html

<div>
 <button name="Save" [ngClass]="['bntStyle']" (onClick)="submit()">Submit</button>
</div>

Answer 1

You are binding the string 'btnStyle'. Instead, you should bind the filed:

<div>
    <button name="Save" [ngClass]="[bntStyle]" (click)="submit()">Submit</button>
</div>

Answer 2

Fire change (OnClick) to (click) and then use following code snippet.

<div>
 <button name="Save" [ngClass]="[bntStyle]" (click)="submit()">Submit</button>
</div>

DEMO