Praxis — An adaptive tutor that shows its working Guest learner

JavaScript › Types and coercion

0/0 this session +0 XP
Multiple choice Easy quirk ~40s

What does typeof null return?

Hints are free to take and they are counted. A correct answer after two hints moves your mastery less than one without — which is the honest way to score it.

Why this question? this skill is new to you; the difficulty is about right — roughly 71% chance you get it; and it needs calibrating — few people have tried it Predicted chance you get it: 71% — the selector aims at 78%.
difficulty fit 0.788
skill need 0.75
review boost 0
calibration bonus 0.12
recency penalty 0
repetition penalty 0
frustration 0