How uncheck checkbox during subscription

In my app I’m using checkboxes based on array of strings this.options [‘test1’, ‘test2’, ‘test3’]
During switch language I would ilke to uncheck all of them:

      this.languageChanged = this.ea.subscribe('i18n:locale:changed', () => {
this.options = [];

But after change this array is still filled :confused: Why?

Observing collections can be unintuitive at times; try this.options.splice(0) instead of resetting the array.

Damn, it works… But why? :thinking:
I didn’t use Observing Collections explicitly.