ngif to check null, undefined and empty + angular 5

<ng-template pTemplate="body" let-rowData let-columns="columns">

                <tr style="height:110px">

                    <td *ngFor="let col of columns" [style.width]="col.width" >

                        <div *ngIf = "rowData[col?.field] != ''">

                                {{rowData[col?.field] || rowData.Control[col?.field] || rowData.Turbo[col?.field]}}

                        </div>

                    </td>

                </tr>

            </ng-template>