use ngclass with ngif tag using angular 8 code example
Example 1: ng class multiple class names
<!-- notice expression1 used twice -->
<div ng-class="{class1 : expression1, class2 : expression1}">
Hello World!
</div>
Example 2: ngclass
content_copy
<some-element [ngClass]="'first second'">...</some-element>
<some-element [ngClass]="['first', 'second']">...</some-element>
<some-element [ngClass]="{'first': true, 'second': true, 'third': false}">...</some-element>
<some-element [ngClass]="stringExp|arrayExp|objExp">...</some-element>
<some-element [ngClass]="{'class1 class2 class3' : true}">...</some-element>