Developing Software

Question 1

Name the three main constructs of programming

Answer 1

Sequence, selection and iteration

Question 2

Describe the ‘sequence’ construct of programming

Answer 2

Sequence is the process of a program running instructions one after the other, from the top of the program to the bottom

Question 3

What is a syntax error caused by

Answer 3

A syntax error is caused by the failure of the programmer to use the correct grammatical rules of the language

Question 4

What is a run-time error caused by

Answer 4

A run-time error occurs when the user directs the computer to perform an illegal operation, e.g. Dividing a number by zero, assinging a variable to the wrong type of variable, using a variable in a program before assigning a value to it, etc.

Question 5

What makes logic errors the hardest errors to detect in a program

Answer 5

They are the hardest to detect as they do not halt the program

Question 6

Describe black box testing

Answer 6

Black box testing treats the system as one that cannot be seen in detail. The structure of the program is not taken into account. The tests are based on what the program does.

This approach should generally be performed as so:
Code and unit test a component
Add the component to the existing combination
Test and debug the new combination

Question 7

Describe white box testing

Answer 7

White box testing treats the system as one in which the workings can be seen. The structure of the program is taken into account when tests are designed for the program. It should do the following:
Guarantee all statements in the program have been tested at least once
Test all decision statements on their true and false side and check to see which paths have not been tested in the black box approach
Test all loops at their boundaries and their operational limits
Exercise internal data structures to check their validity
Create new test data for paths not already tested

Question 8

Name the three main categories test data can be divided into

Answer 8

Normal, extreme and exceptional

Question 9

Describe normal test data

Answer 9

Data input that is likely that the program will process during a typical run

Question 10

Describe extreme test data

Answer 10

Data input that is not typical and may occur at the boundaries of the programs processing

Question 11

Describe exceptional test data

Answer 11

Data input that is incorrect and will need to be validated by the program to prevent the program giving incorrect results or crashing

Question 12

State the five parts a technical guide is composed of

Answer 12

Project brief
Specification document
Design document
Program code listing 
Test documentation

Question 13

Describe a project brief

Answer 13

A project brief sets out the general requirements of a client from a system. It is written in non-technical terms and acts as a reference for the programming team. Used as the basis for the creation of the software requirements specification

Question 14

Describe what a software requirements specification includes and why it is used

Answer 14

The project brief is normally not detailed enough for implementation. The software requirements specification is a complete statement of the functional and informational requirements of the proposed system.

Its structure will be similar to this:
Introduction
Information description
Functional description

Question 15

Describe a design document

Answer 15

The design document shows the architectural design of the system. Architectural design is concerned with the overall organisation of a software system. The main idea is to use functional decomposition.

Question 16

Describe functional decomposition

Answer 16

The process of using the subprogram facility available in most high-level languages to decompose a problem into simpler sub-problems which can be handled seperately.
Each software component is called a module and the process is also known as modular design.

Normally described as a top-down approach

Question 17

Describe a stack pointer and its function

Answer 17

The stack pointer is a register that stores the address of the last program request in a stack

Question 18

Describe a stack

Answer 18

A stack is a specialised buffer which stores data from the top down

Question 19

Where is a data dictionary found and what does it include

Answer 19

A data dictionary is normally found within the specification document and includes variable names, data types, descriptions and scopes.

Question 20

Describe how you would solve a software issue using the troubleshooting process

Answer 20

Identify symptoms of problem
Find out where problem lies - could be within the design, code etc.
Isolate the problem to one part of the program
Desk check the code
Make corrections to code
When corrected, update the documents and document the solution to the problem