How to set first option selected in ionic 4 select popover

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#1 
 <ion-select header="select Device Family"  interface="popover" (ionChange)="change($event)" [selectedText]="selectedDeviceFamily.name">
                <ion-select-option *ngFor="let table of tables" [value]="table">{{table.name}}</ion-select-option>
        </ion-select>
#2

Use [(model)]="xx" and set xx to a default value in your class.

#3