Lesson 02 · 15 min
Arrays and hash tables
Why index access is instant while search is not, and how a Map saves you from nested loops.
15 minLesson 2 of 8Practice includedAsk AI on any point
An array stores its elements next to each other. That is why arr[i] is O(1): the address of the element can be computed right away. But finding an element by value is only possible by scanning: indexOf and includes run in O(n).
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