vuejs v-model, multiple checkbox and computed property

Question

I am trying to use multiple checkboxes in single file component. And I need to computed property, but I have boolean newVal instead of array in my setter. Here is my code:

Answer 1

Properties that start with _ or $ will not be proxied on the Vue instance because they may conflict with Vue’s internal properties and API methods. You will have to access them as vm.$data._property.

From the official documentation.