Coding Styles

Jussi Pohjolainen

Tampere Polytechnic University of Applied Sciences » ICT

Why Coding Styles are important?

• Code readibility
• Maintenence
• Professionalism
• Code consistancy

Documentation language

• Write everything in English
  • Comments
  • Function names
  • Variable names
  • Documentation

Naming variables

• Use descriptive names. Do not use variable names like $a, $b etc.
• For multiword variable names, use mixed case or underscores:
  • $numElements or $num_elements
• Global Variables: use all-uppercase. Example $PATH = "/foo/bar";
• Function names: all lowercase, mixed case or underscores: function print_name($name)
• Class names: First letter capitalized, mixed case: class RssReader
• Be consistent!

Code Formatting: indentation

• You should always indent your code
• Use soft tabs!
• Example in PHP:

  if($something == 'foo')
  {
  _ _ _ _while($bar) // soft tab = 4 spaces
  _ _ _ _{
  _ _ _ _ _ _ _ _print 'bar';
  _ _ _ _}
  }
  

Code formatting: Line Length

• Try to break up any line that is longer than 80 characters
• Standard Unix terminal windows is set to 80 chars (readibility)
• Example of breaking line (in PHP):

  mail("postmater@hotmail.com",
       "Subject",
       "Body of he message",
       "From: Donald Duck \r\n");
  

Code Formatting: Whitespace

• Use whitespace to provide logical structure in your code.
• Hard to read:

  $name = "Pekka";
  $email = "pekka@gmail.com";
  $address = "Hämeenkatu 1, 33200 Tampere, Finland";
  $sex = "male";
  

• Fixed with whitespace:

  $name    = "Pekka";
  $email   = "pekka@gmail.com";
  $address = "Hämeenkatu 1, 33200 Tampere, Finland";
  $sex     = "male";
  

Using Braces in Control Structures

• Use always braces!
• Use consistently braces, three styles:

• if ($condition)
  {
  }

• if ($condition)
    {
    }
  

• if ($condition) { 
  
  }
  

• There is no right answer, what brace-style is best.
• If there is a official recommendation which brace-style should be used in a certain language, then follow the recommendation.
• Choose one and stick with it. Do not mix styles.

Documentation

• Commenting your code is very important.
• Every class and function should be commented.
• In many languages there are tools that generate documentation from comments (JavaDoc, PhpDocumentor). In those languages comments should be done in a certain way.