How to pass value to ngClass?

Question

Angular

There is such a template.
<div [ngClass]="_bodyClass"></div>
On the first load, all classes are applied, but when the _bodyClass is further changed on the template, nothing happens, although if you do this,
<div [ngClass]="{'testClass':myVariable}"></div>
everything works. What is the problem?

Answer 1

Пример