Question

Write a program named ArrayDemo that stores an array of 10 integers. (Note that the array is created for you and does not need to be changed.) Until the user enters a sentinel value, allow the user four options: (1) to view the list in order from the first to last position in the stored array (2) to view the list in order from the last to first position (3) to choose a specific position to view (4) to quit the application.

Answer 1

Answer:

Hi Zoom! Good question. This is particularly useful for learning sorting functions in arrays and user input handling as well. Please find the implementation below.

Explanation:

I have implemented the code in Python 2+. You can save the below code into a file called ArrayDemo.py and then run it from the command line with the command "python ArrayDemo.py". I have declared the demo_array in the code to an array of 10 unsorted integer values to test this. You can change the code if needed to have this array input by user as well and it should work fine.

Note: if you're using Python 3+ then you'll need to change the "raw_input" in the code to just "input" to make it work.

ArrayDemo.py

demo_array = [2,1,3,4,5,7,6,8,10,9]

option = 0

while (option != 4):

 option = raw_input("Enter 1 to view list in ascending order, 2 to view list in descending order, 3 to choose specific poisition to view, 4 to quit the application: ")

 try:

   option = int(option)

   if option == 1:

     sort_by = 'asc'

     print(sorted(demo_array, reverse=False))

   elif option == 2:

     sort_by = 'desc'

     print(sorted(demo_array, reverse=True))

   elif option == 3:

     position = raw_input("Enter specific position to view (0-9): ")

     try:

       position = int(position)

       if position < 0 or position > 9:

         print("Position does not exist")

       else:

         print(demo_array[position])

     except ValueError:

       print("Position does not exist!")

   elif option == 4:

     break

   else:

     break

 except ValueError:

   print("Invalid input!")