1. Coding practices
For IT and Computing students
2014

2. Introduction
Superior coding techniques and programming practices are hallmarks of a professional programmer
These slides cover:
fundamental coding techniques to improve the readability and maintainability of code
coding practices to enhance performance
Assignments award marks for good programming
Information adapted from Rob Caron Microsoft Corporation February 2000

3. Techniques: Naming A name should tell “what” instead of “how”
GetNextStudent() instead of GetNextArrayElement()
Use the verb-noun method for naming routines or functions that perform some operation on a given object, such as 
CalculateInvoiceTotal()

4. Techniques: Naming
Use Pascal naming for functions – start with a capital letter
CalculateInvoiceTotal()
Use Camel Case for variables – start with lower case
documentFormatType
Use upper case with underscores for constants
NUM_DAYS_IN_WEEK

5. Techniques: Naming Hungarian and Leszynski/Reddick
Prefixes or tags are used at the front of the variable to indicate type
strUserName
intOrderQuantity
tblUsers
qryGetOrders
Mainly used by Microsoft but discouraged in their latest design guide

6. Techniques: Naming
When naming tables, express the name in the singular form. Spaces are not allowed.
Employee instead of Employees
Avoid single-letter variable names, such as i, or j, other than for x,y,z coordinates
Boolean variable names should contain Is which implies True/False values
fileIsFound

7. Techniques: Naming
Do not use literal numbers or literal strings, such as For dayCount = 1 To 7 
Instead, use named constants,
For dayCount = 1 To NUM_DAYS_IN_WEEK

8. Techniques: Comments Comment as you code
Code which is obvious today probably won't be obvious six weeks from now (or even tomorrow)
Comment anything that is not readily obvious in the code
Comment code that consists of loops and logic branches
Don’t put comments at the end of a line of code unless annotating variable declarations or ending a loop.

9. Techniques: Comments At the beginning of every module or file provide
Name and version of the module.
Purpose of the Module.
Description of the Module (In brief).
Original Author /*
File: connection.php V1.1
By: Bob Date:
This script connects to a database */

10. Techniques: Format
Establish a standard size for an indent, such as 4 spaces
Align sections of code using indentation
If … Then …
Else
End If

11. Techniques: Format
Align open and close braces vertically for (count = 0; count < 100; count++) { … } Or put open braces at the end of the line and close braces at the beginning of the line for (count = 0; count < 100; count++){

12. Techniques: Format
When writing SQL statements, use all uppercase for keywords and mixed case for database elements, such as tables, columns, and views
Put each major SQL clause on a separate line
SELECT FirstName, LastName
FROM Customers
WHERE County = 'Hereford'

13. Practice: General
Select data types to ensure the size of a variable is not excessively large
Keep the scope of variables as small as possible
Use variables and routines for one and only one purpose.
Develop and use error-handling routines
Treat compilation warnings as errors
Use Select Case or Switch statements instead of repetitive checking of a common variable using If…Then statements

14. Practice: Data specific
Never use SELECT *. Always be explicit in which columns to retrieve and retrieve only the columns that are required
Verify the row count when performing DELETE operations
Perform data validation at the client during data entry
Avoid using functions in WHERE clauses