mat select on selection change code example

Example: mat-select onchange event

<mat-form-field>
    <mat-select placeholder="State" (selectionChange)="someMethod($event.value)">
        <mat-option *ngFor="let state of states" [value]="state.value">
            {{ state.viewValue }}
        </mat-option>
    </mat-select>
</mat-form-field>