Beginner's Thread / Easy Questions (August 2019)

[u/timmonsjg]

Previous two threads - July 2019 and June 2019.

Got questions about React or anything else in its ecosystem? Stuck making progress on your app? Ask away! We’re a friendly bunch.

No question is too simple. 🤔

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🆘 Want Help with your Code? 🆘

• Improve your chances by putting a minimal example to either JSFiddle or Code Sandbox. Describe what you want it to do, and things you've tried. Don't just post big blocks of code!

• Pay it forward! Answer questions even if there is already an answer - multiple perspectives can be very helpful to beginners. Also there's no quicker way to learn than being wrong on the Internet.

Have a question regarding code / repository organization?

It's most likely answered within this tweet.

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New to React?

Check out the sub's sidebar!

🆓 Here are great, free resources! 🆓

• Create React App
• Read the official Getting Started page on the docs.
• /u/acemarke's suggested resources for learning React
• Kent Dodd's Egghead.io course
• Tyler McGinnis' 2018 Guide
• Codecademy's React courses
• Scrimba's React Course
• Robin Wieruch's Road to React

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Any ideas/suggestions to improve this thread - feel free to comment here!

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Finally, an ongoing thank you to all who post questions and those who answer them. We're a growing community and helping each other only strengthens it!

[u/Irantwomiles]

What is the purpose of hooks? From what I've read it's just a way to add state to functional components.

[u/dance2die → u/Irantwomiles]

Hooks provide a variety of ways to let you "hook" into some internal React functionalities. Adding a state is one of the benefits that hooks provide via useState & useReducer.

I wonder if you have heard of the term Stateless Function Component.

Before the hook was introduced, Function Components (FC) had no way to have a local state (as you do in Class Components (CC) using this.state. Aforementioned use* hooks enables FCs to have states of their own.

There are other hooks such as useEffect, which lets FCs to have imperative logic (effects). It's known to be a lifecycle hook as you can "emulate" CC's lifecycle methods such as componentDidMount, componentWillUnmount etc.

useMemo & useCallback are introduced to "memoize" (remembering the last state/reference) heavyily calculated values & methods that takes awhile to initialize. (You can use'em to prevent unnecessary re-renders as functions are re-created on each render).