Page 221 - DCAP305_PRINCIPLES_OF_SOFTWARE_ENGINEERING

Unit 10: Coding Standards

Indenting the code yields easier-to-read code, such as: Notes
If … Then
If … Then
…
Else
…
End If
Else
…
End If

• Establish a maximum line length for comments and code to keep away from having to
scroll the source code window and to allow for clean hard-copy presentation.
• Use spaces before and after most operators when doing so does not alter the intent of the
code. For example, an exception is the pointer notation used in C++.
• Put a space after each comma in comma-delimited lists, such as array values and arguments,
when doing so does not alter the intent of the code. For example, an exception is an ActiveX
Data Object (ADO) Connection argument.
• Use white space to provide organizational clues to source code. Doing so creates
“paragraphs” of code, which aid the reader in comprehending the logical segmenting of
the software.
• When a line is broken across several lines, make it obvious that the line is incomplete
without the following line.
• Where appropriate, avoid placing more than one statement per line. An exception is a
loop in C, C++, Visual J++, or JScript, such as for (i = 0; i < 100; i++).
• When writing HTML, establish a standard format for tags and attributes, such as using
all uppercase for tags and all lowercase for attributes. As an alternative, adhere to the
XHTML specification to ensure all HTML documents are valid. Although there are file size
trade-offs to consider when creating Web pages, use quoted attribute values and closing
tags to ease maintainability.
• When writing SQL statements, use all uppercase for keywords and mixed case for database
elements, such as tables, columns, and views.
• Divide source code logically between physical files.
• In ASP, use script delimiters around blocks of script rather than around each line of script
or interspersing small HTML fragments with server-side scripting. Using script delimiters
around each line or interspersing HTML fragments with server-side scripting increases
the frequency of context switching on the server side, which hampers performance and
degrades code readability.
• Put each major SQL clause on a separate line so statements are easier to read and edit,
for example:
SELECT FirstName, LastName
FROM Customers
WHERE State = ‘WA’
• Do not use literal numbers or literal strings, such as For i = 1 To 7. Instead, use named
constants, such as For i = 1 To NUM_DAYS_IN_WEEK, for ease of maintenance and
understanding.

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