摘要：
In this lesson we take all of the hooks and logic from our <ExchangeRate> component and put them into a custom hook called useCurrencyCodes(). What's 阅读全文
摘要：
With React hooks it's common to write callback functions in our component body. Event handlers are a common example of this. Most of the time they wor 阅读全文
摘要：
In addition to storing DOM references, the useRef hook can be used to store values without re-rendering the component. If you have a class component t 阅读全文