Code Structure
It is important to have a logical structure to programs. Programs should be organized so developers and maintainers can easily determine what modules and routines perform what function.
Definitions
Program - A program is an organization of modules that are assembled to provide a business function.
Module - A module is a set of functions which implement one concept. For example a module may support database access. A module is usually a collection of functions in one file but may require several related files.
Function - A function is a relatively short part of code that performs one specific function. A function should not be longer than one page. An example of a function is code that prints a string. Functions are typically used multiple times inside the program.
Interface - An interface is a function (also called a method) which is used by a function or module to communicate with other parts of the program.
Structured Programming Rules
Structured programming and keeping a program intellectually manageable depends upon adherance to structured programming rules. The program should be designed from the top down to keep it understandable while using modular design. Some structured programming rules include:
Code no more than one statement per line.
Divide programs into functions.
Functions should perform only one task.
Variable names should be meaningful.
Use of global variables should be avoided.
All variables should be explicitly declared and given an initial value.
Hierarchial data structures should be used to keep the data and program structured.
Each function must have an initial comment which explains:
What its purpose or use is.
What arguments it requires or accepts and what their use is.
What value(s) the function returns.
What values or parts of the program the function may change.
Algorithms used.
Conditions which may cause the program to fail.
The creator of the function.
The date the function was created.
The version number of the function.
Compound conditional statements should be limited to avoid confusion.
Indentation should be consistent.
When used in functions, the use of { and } should be on their own lines to demark blocks of code.
Upper case should be used for defined static constants.
For all keywords and variables, use lower case.
Use simple incrementer variables for loops such as the Fortran integer variable names which are i, j, k, l, m, and n.
In graphics or coordinates, use variables x, y, and z for coordinates.
Coding Structure
Stored procedures are to be for database access.
Modules are used to group program functions into a unit or single file containing related program functions. This makes it easier to find functions when analyzing or writing the program code. Modules should be designed to be generic when possible so they may be used in other applications. This will improve quality of code by re-using code that is already checked against quality standards and tested.
|
|