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

If you have array of Int's. Each int is 32 bit's in java . If you have for example 10 integers in java it means you allocate memory of 320 bits. Then computer know

0 - index is at memory for example - 39200

last index is at memory 39200 + total memory of your array = 39200+320= 39520

So then if you want to access index 3. Then it is 39200 + 32*3 = 39296.

It all depends how much memory your object takes which you store in array. Just remember arrays take whole block of memory.