Coding%20Practices

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Coding Practices
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Why do we care?

• Good code is more than just functionality
• Other people will read your code
• You will forget what you code does
• Debugging bad code is time consuming and
  frustrating

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Basic Coding Practices

• Use meaningful names
• Dont duplicate code
• Dont reinvent the wheel
• Use comments effectively
• Test early and often
• Code maintenance

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Names

• Give functions and variables meaningful names
• Bad names include temp, integer1, l

int l 6 if (1 6) print(true) else
print(false)
What is the output from this piece of code?
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Names

• Give functions and variables meaningful names
• Bad names include temp, integer1, l

int l 6 if (1 6) print(true) else
print(false)
What is the output from this piece of code?
Output is false. The variable in line 1 is a
lower case L. In some fonts this is confused with
the character for the number one, as found on the
second line.
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Names

• Bad names make code hard to read and understand

What does this code do?

• int func1(int a, int b)
• if (a lt 24 b lt 60)
• return 1
• else
• return 0

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Names

• Bad names make code hard to read and understand

How about this code?
What does this code do?

• int func1(int a, int b)
• if (a lt 24 b lt 60)
• return 1
• else
• return 0

int validateTime(int hours, int minutes) if
(hours lt 24 minutes lt 60) return
1 else return 0
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Code Duplication

• Duplicated code adds confusion
• Duplicated code leads to more bugs
• Replace duplicated code with functions

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Reinventing the Wheel

• The I can do it better trap
• Read and understand support code, especially so
  called helper functions
• Explore the standard libraries
• e.g. www.cppreference.com

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Comments

• Comments help the reader understand the code
• Bad comments include
• repeating what the code does
• lengthy explanations of badly written code

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Comments

• Good comments include
• summarizing blocks of code
• describing the programmers intent
• identifying logical divisions in the code
• identifying unconventional methods

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Testing

• Test early and often dont write everything and
  the start testing
• Identify separate components that can be tested
  individually Code in Blocks
• If necessary write your own test cases, but start
  small
• Test user inputs (and function inputs)

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Code Maintenance

• Periodically backup your work
• Every time you get a particular feature to work,
  save a copy of your files
• More advanced source control RCS or CVS