A programmer is writing a program to manage a list of phone numbers. The program needs to be able to add a new phone number, delete an existing phone number and change an existing phone number. The phone numbers are stored in an array called `phonenumberlist`.

Mark scheme

Marking points from the official mark scheme. The mark or mark type is shown in brackets.

1. 8(a) M1 for input, A1 for adding, A1 for increasing length, M1 for logic.
2. GET newPhoneNumber (1)
3. phonenumberlist.append(newPhoneNumber) (1) (Alternative: phonenumberlist[length] = newPhoneNumber)
4. length = length + 1 (1)
5. Clear indication of adding to end of list / array, or inserting at a specific point with shifting (1)
6. 8(b) Up to two of: B1 for each feature, B1 for explanation.
7. Use of clear menus / instructions (1) (Explanation: Allows users to understand options and navigate easily) (1)
8. Consistent layout / design (1) (Explanation: Makes the program predictable and easy to use) (1)
9. Use of meaningful error messages (1) (Explanation: Helps users understand what went wrong and how to fix it) (1)
10. Use of appropriate colours / fonts (1) (Explanation: Improves readability and visual appeal) (1)
11. Use of help screens / tutorials (1) (Explanation: Provides guidance for new or confused users) (1)
12. Use of graphical user interface (GUI) instead of command line (1) (Explanation: Provides visual elements, making it more intuitive) (1)
13. Easy navigation (e.g. back buttons) (1) (Explanation: Users can easily move between different parts of the program) (1)