Computed properties are data in Vue components that depend on some calculation on other, more primitive data. When this primitive data is reactive, the computed properties are up-to-date and reactive themselves. In this context, primitive is a relative term. You can certainly build computed properties based on other computed properties.
Learning how to use computed properties
Getting ready
Before venturing to prepare this recipe, be sure to familiarize yourself with the v-model directive and the @event notation. You can complete the React to events like clicks and keystrokes recipe in the preceding chapter if you are unsure.