Vue's Vue.set dynamic new Object properties

when we add a new attribute to an object such as props, or data that is observed, it cannot be added directly, and the Vue.set method must be used The Vue.set method is used to add properties to the object. If the object to which you want to add a property is responsive, this method ensures that the property is also responsive after it is created, triggering the view update

The food object here is not the Count property, we have to add the Count property to it must use the Vue.set method, and cannot be written as ' This.food.count = 1 '