Angular Mat Select Multiple selectionchange finding which option was changed

Question

I have a with the multiple option set (a multi-select). When the selectionChange event fires I need to know which o

Answer 1

This worked for me. blahs is an array of strings in this case. Use 2-way binding:

<mat-select placeholder="choose..." [(value)]="selected" 
      (selectionChange)="somethingChanged(selected)">
  <mat-option *ngFor="let b of blahs; index as i;" value={{b[i]}}">{{b[i]}}
  </mat-option>
</mat-select>

Answer 2

I needed to use onSelectionChange on the <mat-option>, which is different than the selectionChange that you can use on the <mat-select>

It would be nice if that was in the documentation for mat-select.

Here it is working https://stackblitz.com/edit/angular-1e9gsd-34hrwg?file=app/select-overview-example.html