Why is accessing any single element in an array done in constant time ( O(1) )?

Question

According to Wikipedia, accessing any single element in an array takes constant time as only one operation has to be performed to locate it.

To me, what happens behi

Answer 1

In theory elements of an array are of the same known size and they are located in a continuous part of memory so if beginning of the array is located at A memory address if you want to access any element you have to compute its address like this:

A + item_size*index so this is a constant time operation.