how to switch to angular 8 code example
Example: *ngSwitch
<container-element [ngSwitch]="switch_expression">
<!-- the same view can be shown in more than one case -->
<some-element *ngSwitchCase="match_expression_1">...</some-element>
<some-element *ngSwitchCase="match_expression_2">...</some-element>
<some-other-element *ngSwitchCase="match_expression_3">...</some-other-element>
<!--default case when there are no matches -->
<some-element *ngSwitchDefault>...</some-element>
</container-element>