Dear @1001albertpadilla

Try to use *ngIf directive to get this effect:

HTML:

<div class="md-form">
        <input
          (keyup)="onInput($event.target.value)"
          mdbInput
          type="text"
          id="form1"
          class="form-control"
        />
      <label for="form1" *ngIf="value.length > 0" class="">Last Name</label>
      <label for="form1" *ngIf="value.length === 0" class="">* Last Name</label>
 </div>

TS:

 value = '';
  onInput(e: string) {
    this.value = e;
  }

Hope it helps!

Sorry for the upload failure, we will try to fix it as soon as possible

Best Regards, Bartosz.