Question

I can't seem to find this answer anywhere else, can you take a number out of a variable and use it to define an entry of an array? We don't know how long the array is because the computer program randomizes it every time we reset the code (hence the 'len()' code) .
In more straight talk:
Line 1: variable1 = number_of_entries = len(array)
Line 2: variable2 = array[variable1]
Please help im dumb