React · Senior · Question 74 of 75

What happened to `propTypes` on function components in React 19?

✓Correct answer: Runtime prop-type checking was removed; use TypeScript or another validation tool
2They became mandatory
3They are now checked at compile time by React

Explanation

React 19 silently ignores propTypes. Static types catch the same errors earlier, and schema validation (e.g. Zod) handles external data.

Further reading

React 19 Upgrade Guide ↗

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