Summary

In this chapter, you learned what the concept of state is in React. You dug deeper into the useState design, which is divided into mounting a state and updating a state. We learned about various ways of dispatching states and ways to determine if a state has changed. Then, we also learned that a dispatch can support a value format or a functional updater format, and we learned that we can dispatch multiple times in one event handler. Then, we took useState for a test drive and learned how to send the state change to a child component via props. We also learned a common technique called lifting up, which involves lifting a state up to a parent. Last but not least, we designed two components – an avatar component and a tooltip component – to learn how to apply useState in the design of components.

In the next chapter, we will explore our second hook in the React family. We will also see how React defines an action called effect and allows you to invoke it after...