Praxis — An adaptive tutor that shows its working Guest learner

JavaScript › Arrays and iteration

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Multiple choice Moderate mutationgotcha ~60s

Which of these array methods MUTATES the array it is called on?

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; it stretches you slightly; and it needs calibrating — few people have tried it Predicted chance you get it: 45% — the selector aims at 78%.
difficulty fit 0.022
skill need 0.75
review boost 0
calibration bonus 0.12
recency penalty 0
repetition penalty 0
frustration 0