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Question 113

What happens when reduce is called on an empty array without supplying an initial accumulator value?

  1. It throws a TypeErrorBonne réponse
  2. It returns undefined
  3. It returns zero for every reducer
  4. It skips the call and returns the empty array

Explication

With no elements and no explicit initial value, reduce has nothing from which to establish its accumulator, so it throws a TypeError. Supplying an initial value would make that value the result for the empty array instead.

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Question 113: What happens when reduce is called on an empty array… · JavaScript Fundamentals · Questena