Code is read many more times than written

"Code is read many more times than written." - this statement changed my view of Software Engineering. From that point on I made it my personal mission to write the best code I could possibly write.
This talk is about my very favorite coding wisdoms that I picked up on my journey so far. All of these will help you to write better code, be more productive and have more fun. And good code pays it's interest rate every day.
Also if you're a clean code junkie looking for a fix - this talk is for you.

Transcript

1. We write code
   

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2. Isn't it more about
   reading?
   

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3. Written once – read many
   times
   

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4. „(…) when you program,
   you have to think about
   how someone will read
   your code, not just how a
   computer will interpret it.“
   Kent Beck
   

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5. Not about
   Architecture
   

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6. Methods & Code
   

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7. Extra effort
   

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8. Save time
   

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9. Your code base?
   

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11. It's about joy!
    

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12. Code is read many more times
    than written
    Tobias Pfeiffer
    @PragTob
    pragtob.wordpress.com
    

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13. Sources
    

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14. Crazy?
    

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15. Are comments a smell?
    

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16. Outdated comments are the
    worst
    

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17. The why not the what
    

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18. Comments are an excuse of
    the code that it could not be
    clearer.
    

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19. # do one thing
    …
    …
    …
    # do another thing
    …
    …
    …
    # do something more
    …
    …
    

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20. Extract Methods
    

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21. do_one_thing
    do_another_thing
    do_something_more
    

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22. # context, outlet, times, time per
    step, state, data
    def pattern(c, o, t, l, s, d)
    # …
    end
    

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23. Explanatory and meaningful
    names
    

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24. def pattern(context, outlet, time,
    time_per_step, state, data)
    # …
    end
    

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25. Try to keep it to 2 parameters
    

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26. Argument order dependency
    

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27. No magic numbers
    

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28. Explanatory variable
    

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29. Short Methods (<= 8 LOC)
    

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30. # allowed to drink?
    if customer.age > 18
    say 'Okay'
    prepare_drink requested_drink
    say 'here you go'
    hand_drink_over drink, customer
    else
    say 'I am sorry you are not legally
    allowed rather to drink here'
    say "Would you rather have a
    #{NON_ALCOHOLIC_DRINKS.sample}?"
    end
    

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31. # allowed to drink?
    if customer.age > 18
    say 'Okay'
    prepare_drink requested_drink
    say 'here you go'
    hand_drink_over drink, customer
    else
    say 'I am sorry you are not legally
    allowed rather to drink here'
    say "Would you rather have a
    #{NON_ALCOHOLIC_DRINKS.sample}?"
    end
    

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32. Query method
    

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33. Intention revealing method
    

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34. # …
    text.color = red
    # …
    

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35. def highlight(text)
    text.color = red
    end
    

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36. # …
    highlight(text)
    # …
    

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37. if customer.age > 18
    say 'Okay'
    prepare_drink requested_drink
    say 'here you go'
    hand_drink_over drink, customer
    else
    say 'I am sorry you are not legally
    allowed rather to drink here'
    say "Would you rather have a
    #{NON_ALCOHOLIC_DRINKS.sample}?"
    end
    

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38. if customer.age > 18
    say 'Okay'
    prepare_drink requested_drink
    say 'here you go'
    hand_drink_over drink, customer
    else
    say 'I am sorry you are not legally
    allowed rather to drink here'
    say "Would you rather have a
    #{NON_ALCOHOLIC_DRINKS.sample}?"
    end
    

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39. if customer.age > 18
    say 'Okay'
    prepare_drink requested_drink
    say 'here you go'
    hand_drink_over drink, customer
    else
    say 'I am sorry you are not legally
    allowed rather to drink here'
    say "Would you rather have a
    #{NON_ALCOHOLIC_DRINKS.sample}?"
    end
    

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40. if customer.age > 18
    say 'Okay'
    prepare_drink requested_drink
    say 'here you go'
    hand_drink_over drink, customer
    else
    say 'I am sorry you are not legally
    allowed rather to drink here'
    say "Would you rather have a
    #{NON_ALCOHOLIC_DRINKS.sample}?"
    end
    

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41. if allowed_to_drink_alcohol?(customer)
    serve_drink requested_drink,
    customer
    else
    propose_non_alcoholic_drink
    end
    

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42. „The easiest code to
    understand is the code you
    don't have to read at all.“
    Tom Stuart (Berlin)
    

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43. Same level of abstraction in a
    method
    

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44. prepare_drink requested_drink
    price = requested_drink.price
    Check = Check.new
    check.add_price price
    say 'That whill be ' + check.total
    

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45. prepare_drink requested_drink
    price = requested_drink.price
    Check = Check.new
    check.add_price price
    say 'That whill be ' + check.total
    

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46. prepare_drink requested_drink
    price = requested_drink.price
    Check = Check.new
    check.add_price price
    say 'That whill be ' + check.total
    

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47. prepare_drink requested_drink
    prepare_check requested_drink
    

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48. DRY
    

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49. Nice code formatting
    

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50. @left ||= 0
    @top ||= 0
    @width ||= 1.0
    @height ||= 0
    

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51. double character: 'something weird',
    stateMask: CTRL | modifier,
    KeyCode: character.downcase.ord
    

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52. 80 character
    Width limit
    

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53. 80 character
    Width limit
    

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54. 80 character
    Width limit
    

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55. 80 character
    Width limit
    

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56. 80 character
    Width limit
    

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57. Don't program by coincedence
    

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58. Code bases detoriate
    

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59. No broken windows
    

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62. Magical time?
    

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63. The Boyscout
    Rule
    

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65. TDD
    

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66. 80% Code Coverage
    

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67. 20% is never executed
    

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68. „Incoming messages should be tested for
    the state they return. Outgoing
    command messages should be tested
    to ensure they get sent. Outgoing query
    messages should not be tested.“
    Sandi Metz
    

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69. Know when to
    break the rules
    

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70. If you still like your code from
    two years ago,
    then you are not learning fast
    enough.
    

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71. Enjoy Coding!
    Tobias Pfeiffer
    @PragTob
    pragtob.wordpress.com
    

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72. Sources
    ●
    The Pragmatic Programmer
    ●
    Smalltalk Best Practice Patterns
    ●
    Clean Code
    ●
    Practical Object Oriented Design in Ruby
    

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73. Photo Credit
    ●
    http://officeimg.vo.msecnd.net/en-us/images/MP900439313.jpg
    ●
    http://officeimg.vo.msecnd.net/en-us/images/MC900021328.wmf
    ●
    (CC BY-SA 2.0)
    – http://www.flickr.com/photos/83633410@N07/7658272558/in/photostream/
    – http://www.flickr.com/photos/83633410@N07/7658165122/
    – http://en.wikipedia.org/wiki/File:Kent_Beck_no_Workshop_Mapping_XP.jpg
    ●
    (CC BY-NC-ND 2.0)
    – http://www.flickr.com/photos/andih/86577529/
    – http://www.flickr.com/photos/12584908@N08/3293117576/
    – http://www.flickr.com/photos/jasonlparks/4525188865/
    – http://www.flickr.com/photos/20714221@N04/2293045156/
    ●
    http://www.flickr.com/photos/47833351@N02/5488791911/(CC BY-ND 2.0)
    ●
    (CC BY 2.0)
    – http://www.flickr.com/photos/barry_b/76055201/
    – http://www.flickr.com/photos/25165196@N08/7725273678/
    – http://www.flickr.com/photos/29254399@N08/3187186308/
    ●
    (CC BY-NC-SA 2.0)
    – http://www.flickr.com/photos/dolescum/7380616658/
    – http://www.flickr.com/photos/antonkovalyov/5795281215/
    – http://www.flickr.com/photos/doug88888/2792209612/
    ●
    (CC BY-NC 2.0)
    – http://www.flickr.com/photos/37996583811@N01/5757983532/
    – http://www.flickr.com/photos/sevendead/5650065458/
    

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74. Source pictures
    ●
    http://imagery.pragprog.com/products/59/tpp.jpg
    ●
    http://www.informit.com/ShowCover.aspx?isbn=9780132852111&type=f
    ●
    http://coding-in.net/blog/wp-content/uploads/clean_code.jpg
    ●
    http://www.informit.com/ShowCover.aspx?isbn=9780321721334&type=f
    ●
    http://mendicantuniversity.org/images/logo.png
    

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