How React's setState is evaluated | 2023 React Interview Questions and Answers
If you are preparing for 2023 React Interview, it might be worth to go deep into the execution of setState() function. Why setState is not updating immediately? Why we should use callback setter function in setState? Why using 2 setState in the row is not the best idea? setState asynchronicity is an important idea in React, and I'll try to do my best to help you understand how it really works.
⏱️Timestamps:
00:00 - Introduction
00:23 - Most common problem with setState
00:38 - Analyzing initial problem as JS Engine
01:04 - Breaking React's Rule
01:27 - React Component vs React Element
01:42 - Analyzing direct variable assignment
02:28 - First React's Execution Rule
03:37 - Functions of setState()
03:58 - setState() and direct assignment comparison
04:40 - Second React's Execution Rule
04:59 - Virtual Queue metaphor
05:57 - Analyzing callback execution (the fix)
07:29 - Third React's Execution Rule