Account registration interface and username validation

2025-familiarisation-se-q09 · Multipart · 6 marks

Source: NESA 2025 HSC Software Engineering Familiarisation Q9

Question

An online store allows users to register for an account using their name, phone number and date of birth. Users must also create a username and password.

Each username must satisfy these rules.

There must be no more than 8 characters.
Only uppercase and lowercase letters are accepted.
The character < is not allowed, to prevent attempts at injecting code through the username.

Part (a) 3 marks

Design a user interface for registering an account. Clearly label all features.

Diagram workspace

Part (b) 3 marks

Write a function in Python that will check whether a username satisfies the rules.

Reveal answer

Part (a)

A suitable interface includes labelled fields for name, phone number, date of birth, username and password, with a submit/register button and validation feedback.

Part (b)

def valid_username(username):
    if len(username) > 8:
        return False
    for character in username:
        if not character.isalpha():
            return False
    return True

Marking rubric

Part (a)

Marks	Description
3	Designs a labelled interface with all required fields and appropriate controls.
2	Designs an interface with most required fields.
1	Shows some relevant interface elements.

Part (b)

Marks	Description
3	Provides a correct Python function that checks length and accepted characters.
2	Provides a mostly correct validation function.
1	Shows some understanding of validation.

Explanation

The < character is excluded by allowing only alphabetic characters. A full solution may also provide feedback explaining why an invalid username was rejected.

Metadata

Submitter: Seed data
Created: 2026-05-02
Status: published
Syllabus: y12-project-tools-for-ideas-solutions y12-secure-defensive-input-handling
Tags: user interface input validation Python secure input