7. A festival ticket supplier produces a unique ticket validation code with each ticket purchase. This validation code comprises four parts: the buyer's surname, the digits from their postcode, an ID and a randomly generated hexadecimal value. Each part is separated with chevrons (»). • The surname can only contain uppercase letters. • The postcode can only contain digits. • The ID must contain 6 digits. • The hexadecimal value uses digits and / or uppercase letters and can be of any length. • Chevrons (»). Example: ZAKS»63»300700»4BAF76C2D7 Produce a Backus-Naur Form (BNF) definition for the validation code. [6] 8. Explain the use of program version management in software engineering. [8] 9. A local shop has approached a software company to build a web application with the following requirements: • To display all the products they have in store through a modern user interface (UI). • To allow customers to find and filter products through the web application. • To allow staff to login and create, edit, delete and view products through a back-end database. Explain why it will be important to analyse these requirements using decomposition and abstraction. [6] 10. Write a Bubble Sort algorithm in pseudo-code that will sort the contents of a one-dimensional integer array (myArray) into descending order. [9] 11. Explain the ambiguities in natural language syntax compared with computer language syntax. [8] 12. Discuss the importance of promoting professional behaviour given the social changes that have occurred as a result of developments in computing and computer use. You should draw on your knowledge, skills and understanding from a number of areas across your computer science course when answering this question. [12] END OF PAPER 6 © WJEC CBAC Ltd. (A500U10-1)