Time complexity: Arrays

Arrays

Arrays offer random access to their contents through a numeric index. Therefore array access is O(1).

Searching for a given value requires iterating through the array. So array search is O(n).

If you know that the array is sorted in a way that's amenable to binary search, then you can search the array that way and achieve in the best case, array search is O(log n).

Inserting into an array requires you to shift all elements to the right by 1. If we say that on average that means n/2 elements need to be shifted, that devolves to **array insert is O(n)*.

Deleting an element from an array requires you to shift all the elements to the left by 1. By similar logic to the above insertion case, array deletion is O(n).

There is no "worst case" to worry about.