State with useState

Add memory to a component with useState, understand why updates are asynchronous and batched, and learn the rules for updating objects and arrays.

Level

Beginner

Chapters

4

Exercises

2

Reading time

16 min

What you will cover

1. 1. Why State ExistsThe difference between a value that survives a render and one that does not.
2. 2. Updates Are AsynchronousWhy the value does not change immediately, and what batching means for your code.
3. 3. Objects and Arrays in StateWhy you must replace state instead of mutating it, and the patterns for doing so.
4. 4. State in PracticeSharing state between components and building a working counter.

Up next after this one: Events and Conditional Rendering