Angular4 - How to set the value of a selection option dynamically

Question

I have a select list with code -

<select (change)='onGroupChange($event)'> <option *ngFor="let group of groups" value={{group.group_name}}> {{group.group_name}} </option> </select> 

Now I have a group name saved as another variable, and I want to set this as the value of the picklist if it matches any.

Answer 1

 <select (change)='onGroupChange($event)'> <option *ngFor="let group of groups" value={{group.group_name}} [selected]="group.group_name==myVariable"> {{group.group_name}} </option> </select> 

Answer 2

 <select [(ngModel)]="selectedGroup" (ngModelChange)="onGroupChange($event)"> <option *ngFor="let group of groups" [value]="group.group_name"> {{group.group_name}} </option> </select>