arrow_backBACK TO DRILLS
Blue BeltuseeffectlockPREMIUM

Returning null and effects

A component returns null when isVisible is false, but it still contains a useEffect hook. A developer expects the effect not to run while the component renders nothing. What actually happens?

lock

This Drill is Locked

This is a premium drill. Continue on to the next free drill in the sequence.

CONTINUE DRILLarrow_forward
BugDojo
BlogFAQ

© 2026. Carved in code.