title: Angular Material - Multiple Select - Last selected value
body: <p>When working with mat-select, you can subscribe to an event "selectionChange". </p>
  
  <pre class="lang-html prettyprint-override"><code>&lt;mat-select
      [(ngModel)]="value"
      name="someName"
      multiple="true"
      (selectionChange)="handleEvent($event)"
  &gt;
      &lt;mat-option
          *ngFor="let val of values"
          [value]="val"
      &gt;
          {{ val }}
      &lt;/mat-option&gt;
  &lt;/mat-select&gt;
  </code></pre>
  
  <pre class="lang-js prettyprint-override"><code>handleEvent(event: MatSelectChange) {
      console.log(event.value); // =&gt; array of values
  }
  </code></pre>
  
  <p>This will emit a MatSelectChange where you access the current value of the select.</p>
  
  <p>The problem is, when working with multiple selection, the value property will contains an array with all the currently selected values.</p>
  
  <p>What I need, is to know what was the last value the user selected. I have print out the MatSelectChange event to see if there is anything I could use (like, previous values, so I can compare), but, sadly, I don't see anything.</p>
  
  <p>Is it possible to achieve that ?</p>