Vue does not allow dynamically adding new root-level reactive properties to an already created instance. It can use the Vue.set(object, key, value) method to add reactive properties to nested objects.
If objects are directly added to an array, the view will not update, but the correct values can be output; only by using this.$set can the view be updated.
for (let i = 0; i < this.data.length; i++) {
// this.data[i].state = false;
this.$set(this.data[i], 'state', false)
}