Ion-select with "select all" option

Ionic Framework ionic-v3
2

You can controll js.

in html template.

  <ion-item>
    <ion-label>Toppings</ion-label>
    <ion-select [(ngModel)]="toppings" multiple="true">
      <ion-option>Bacon</ion-option>
      <ion-option>Black Olives</ion-option>
      <ion-option>Extra Cheese</ion-option>
      <ion-option>Mushrooms</ion-option>
      <ion-option>Pepperoni</ion-option>
      <ion-option>Sausage</ion-option>
    </ion-select>
  </ion-item>
  <button (click)="read();">select all</button>

in ts.

  private toppings;

  read(){
    this.toppings = ["Bacon", "Black Olives", "Extra Cheese", "Mushrooms", "Pepperoni", "Sausage"];
    console.log(this.toppings);
  }

When you click button ‘select all’, variable ‘toppings’ set all options.

Regards.