The Elements of Programming Style (HackConf 2019)

Transcript

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2. Привет!
   

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5. Божидар
   

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6. @bbatsov
   

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9. Why am I here?
   

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12. size=2
    start=0
    c=['Н', 'Н' ,'Н' ,'Н' ,'Н','Н','Н','Н','Н','Н','Н','Н','Н','Н']
    code_dictionary=Array.new()
    begin_size_code_dictionary=Array.new()
    end_string=String.new()
    code_dictionary=c.uniq.to_a
    decode_dictionary=c.uniq.to_a
    for i in 0...code_dictionary.size
    begin_size_code_dictionary[i]=i
    end
    c.size.times{
    if !code_dictionary.include?(c[start,size].to_s)#Comparation
    code_dictionary.push(c[start,size].to_s.chomp)
    start=start+(code_dictionary.last.size)/2-1
    size=2
    else
    size+=1;
    end
    }
    end_code=Array.new(code_dictionary.size)
    for i in begin_size_code_dictionary.size...code_dictionary.size
    end_code[i]=code_dictionary.index(code_dictionary[i].chop.chop)+1
    end_string+=code_dictionary[i].chop.chop
    end
    govnokod.ru
    

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13. The Elements
    of
    Style
    in
    Programming
    by Bozhidar Batsov
    

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14. Languages are hard
    

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16. Basic usage of a
    language is easy
    

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17. Айн-цу-цвайн-цу-дрън
    

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18. "Ту партс,
    съмтаймс люн,
    съмтаймс уин,
    соу,
    фърст дей релякс"
    

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19. The correct usage of
    a language is hard
    

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20. The effective usage of a
    language is very hard
    

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22. Българската политика
    е лайно в целофан.
    

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23. На малко прасе и нов
    началник никога не се
    радвам.
    

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24. Всичко хубаво в тая държава сме
    го направили ние, те не могат да го
    боядисат - от метрото до Северната
    дъга, Тракия, Марица, Струма…
    

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25. Живков и царя са ми като два
    университета. В една тема и двамата
    бяха много единни, че България и
    държавата са над всичко.
    

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26. Да мачкаш Цветанов е
    все едно с голо дупе
    таралеж да мачкаш.
    

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27. not really
    

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28. try 10 years
    

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29. http://norvig.com/21-days.html
    Teach Yourself
    Programming in Ten Years
    Peter Norvig
    

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31. Laziness is a virtue
    

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33. Use the active voice.
    

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34. My first visit to Pernik will always
    be remembered by me.
    lame
    

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35. I shall always remember my
    first visit to Pernik.
    legit
    

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36. The word personally
    is often unnecessary.
    

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37. Personally, I love Emacs.
    

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38. A Style Guide
    • a curated set of (supposedly) good practices
    • spares you the process of making trivial
    decisions
    • allows you to focus on the actual problems
    • simple and concise
    

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39. Style guides aren’t a
    replacement for
    thinking
    

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40. Programs must be
    written for people to
    read, and only
    incidentally for
    machines to execute.
    — Hal Abelson
    

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41. Similar rules apply to
    natural and
    programming languages
    

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43. English
    

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44. Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod
    tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim
    veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea
    commodo consequat. Duis aute irure dolor in reprehenderit in voluptate
    velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat
    cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id
    est laborum.
    Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod
    tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim
    veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea
    commodo consequat. Duis aute irure dolor in reprehenderit in voluptate
    velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat
    cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id
    est laborum.
    Chapter I
    

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45. LOREM IPSUM DOLOR SIT AMET, CONSECTETUR ADIPISCING ELIT, SED DO
    EIUSMOD TEMPOR INCIDIDUNT UT LABORE ET DOLORE MAGNA ALIQUA. UT
    ENIM AD MINIM VENIAM, QUIS NOSTRUD EXERCITATION ULLAMCO LABORIS
    NISI UT ALIQUIP EX EA COMMODO CONSEQUAT. DUIS AUTE IRURE DOLOR
    IN REPREHENDERIT IN VOLUPTATE VELIT ESSE CILLUM DOLORE EU FUGIAT
    NULLA PARIATUR. EXCEPTEUR SINT OCCAECAT CUPIDATAT NON PROIDENT,
    SUNT IN CULPA QUI OFFICIA DESERUNT MOLLIT ANIM ID EST LABORUM.
    LOREM IPSUM DOLOR SIT AMET, CONSECTETUR
    ADIPISCING ELIT, SED DO EIUSMOD TEMPOR INCIDIDUNT UT
    LABORE ET DOLORE MAGNA ALIQUA. UT ENIM AD MINIM
    VENIAM, QUIS NOSTRUD EXERCITATION ULLAMCO LABORIS
    NISI UT ALIQUIP EX EA COMMODO CONSEQUAT. DUIS AUTE
    IRURE DOLOR IN REPREHENDERIT IN VOLUPTATE VELIT
    ESSE CILLUM DOLORE EU FUGIAT NULLA PARIATUR.
    EXCEPTEUR SINT OCCAECAT CUPIDATAT NON PROIDENT,
    SUNT IN CULPA QUI OFFICIA DESERUNT MOLLIT ANIM ID
    EST LABORUM.
    chapter i
    

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46. Български
    

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47. Правителство трябва да има на всяка цена, каза премиерът
    проф. Георги Близнашки пред журналисти в Котел, където беше
    по повод Деня на будителите. "Силно се надявам, че в
    следващите няколко дни, особено след като бъде връчен
    проучвателен мандат, разговорите ще придобият по-спокоен тон
    и ще се стигне до съставяне на правителство", заяви министър-
    председателят, цитиран от правителствената информационна
    служба.
    Той прогнозира тежки първи месеци за следващия кабинет,
    който трябва да предприеме неотложни и "не особено популярни
    мерки". Близнашки изрази надежда, че след това нещата ще
    тръгнат във възходяща линия, благодарение на финансовия
    ресурс, предвиден за страната ни по Споразумението за
    партньорство на ЕК с България до 2020 година.
    Глава 1
    

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48. ПРАВИТЕЛСТВО ТРЯБВА ДА ИМА НА ВСЯКА ЦЕНА, КАЗА
    ПРЕМИЕРЪТ ПРОФ. ГЕОРГИ БЛИЗНАШКИ ПРЕД ЖУРНАЛИСТИ В
    КОТЕЛ, КЪДЕТО БЕШЕ ПО ПОВОД ДЕНЯ НА БУДИТЕЛИТЕ.
    "СИЛНО СЕ НАДЯВАМ, ЧЕ В СЛЕДВАЩИТЕ НЯКОЛКО ДНИ,
    ОСОБЕНО СЛЕД КАТО БЪДЕ ВРЪЧЕН ПРОУЧВАТЕЛЕН МАНДАТ,
    РАЗГОВОРИТЕ ЩЕ ПРИДОБИЯТ ПО-СПОКОЕН ТОН И ЩЕ СЕ
    СТИГНЕ ДО СЪСТАВЯНЕ НА ПРАВИТЕЛСТВО", ЗАЯВИ
    МИНИСТЪР-ПРЕДСЕДАТЕЛЯТ, ЦИТИРАН ОТ ПРАВИТЕЛСТВЕНАТА
    ИНФОРМАЦИОННА СЛУЖБА.
    гЛаВа 1
    ТОЙ ПРОГНОЗИРА ТЕЖКИ ПЪРВИ МЕСЕЦИ ЗА СЛЕДВАЩИЯ
    КАБИНЕТ, КОЙТО ТРЯБВА ДА ПРЕДПРИЕМЕ НЕОТЛОЖНИ И "НЕ
    ОСОБЕНО ПОПУЛЯРНИ МЕРКИ". БЛИЗНАШКИ ИЗРАЗИ
    НАДЕЖДА, ЧЕ СЛЕД ТОВА НЕЩАТА ЩЕ ТРЪГНАТ ВЪВ
    ВЪЗХОДЯЩА ЛИНИЯ, БЛАГОДАРЕНИЕ НА ФИНАНСОВИЯ РЕСУРС,
    ПРЕДВИДЕН ЗА СТРАНАТА НИ ПО СПОРАЗУМЕНИЕТО ЗА
    ПАРТНЬОРСТВО НА ЕК С БЪЛГАРИЯ ДО 2020 ГОДИНА.
    

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49. Ruby
    

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50. def some_method
    do_something
    do_more
    do_more
    end
    

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51. def some_method
    do_something
    do_more
    do_more
    end
    

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52. sum = 1 + 2
    a, b = 1, 2
    [1, 2, 3].each { |e| puts e }
    class FooError < StandardError; end
    

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53. sum=1+2
    a,b=1,2
    [1,2,3].each{|e|puts e}
    class FooError

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54. Elementary Rules of
    Usage
    

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55. English
    

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56. Form possessive
    singular of nouns by
    adding ’s.
    

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57. Bozhidar’s talk
    Batman’s batclaw
    Emacs’s magic
    

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58. Ruby
    

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59. Form predicate method
    names by adding “?”.
    

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60. even?
    completed?
    batman?
    

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62. Elementary Principles of
    Composition
    

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63. English
    

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64. Make the paragraph
    the unit of composition.
    

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65. Ruby
    

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66. Make the method the
    unit of composition.
    

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67. English
    

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68. Omit needless words.
    

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69. he is a man who
    

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70. Her story is a strange
    one.
    

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71. Ruby
    

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72. Omit needless words.
    

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73. if some_condition then
    # body omitted
    end
    

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74. def some_method
    # ...
    return result
    end
    

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76. Words and Expressions
    Commonly Misused
    

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77. English
    

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78. farther
    further
    

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79. Do we have to go
    much farther?
    

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80. I decided to pursue
    the subject further.
    

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81. Ruby
    

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82. ==
    ===
    equal?
    eql?
    

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84. An Approach to Style
    

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85. Be consistent
    

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86. English
    

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87. The user should update
    his config accordingly.
    They should also check…
    

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88. The user should update
    his config accordingly.
    They should also check…
    

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89. Ruby
    

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90. def something coll
    coll.collect(&:ala)
    end
    def something2(coll)
    coll.map { |x| x.bala }
    end
    

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91. Be clear
    

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92. Български
    

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93. БМВ
    

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94. Бързо мощно возило
    

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95. КТБ
    

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96. Коварен
    Терански
    Батълкруузър
    

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97. АБПФК
    

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98. Активен борец против
    фашизма и капитализма
    

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99. Ruby
    

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100. $:
     

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101. $LOAD_PATH
     

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102. $;
     

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103. $FIELD_SEPARATOR
     

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104. $*
     

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105. $ARGV
     

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106. '%d %d' % [20, 10]
     

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107. sprintf('%d %d', 20, 10)
     

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108. sprintf(
     '%{first} %{second}',
     first: 20, second: 10
     )
     

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109. format('%{first} %{second}',
     first: 20, second: 10)
     

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110. Ruby
     is
     optimized
     for
     programmer
     happiness
     

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111. Ruby is a huge
     language
     

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112. Making the “right”
     decisions is hard
     

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114. puts "Hello, HackConf!"
     puts "Hello, HackConf!"
     puts "Hello, HackConf!”
     

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115. for i in 1..3
     puts "Hello, HackConf!”
     end
     

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116. 3.times do
     puts "Hello, HackConf!”
     end
     

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117. result = []
     names.each do |word|
     result << name.upcase
     end
     

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118. names.map { |name| name.upcase }
     

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119. names.map(&:upcase)
     

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120. names.map(_1.upcase)
     

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123. Are all those options
     even worth our while?
     

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126. View Slide

127. 56 simple rules
     

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128. Format a program
     to help the reader
     understand it.
     

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129. Write clearly --
     don't be too clever.
     

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130. def user_signed_in?
     !!@current_user
     end
     def user_signed_in?
     !@current_user.nil?
     end
     

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131. Don't sacrifice
     clarity for small
     gains in efficiency.
     

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132. i = 1
     res = 0
     while i <= 10
     res += i
     i += 1
     end
     

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133. (1..10).reduce(:+)
     

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134. (N * (N + 1)) / 2
     

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135. (10 * (10 + 1)) / 2
     

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136. Don't diddle code to
     make it faster -- find a
     better algorithm.
     

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137. •Make it right before you make
     it faster.
     •Make it fail-safe before you
     make it faster.
     •Make it clear before you make
     it faster.
     

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138. Instrument your
     programs. Measure
     before making efficiency
     changes.
     

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139. Use variable names
     that mean something.
     

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140. a
     s
     l
     

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141. age
     sex
     location
     

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142. age_over_18?
     

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143. adult?
     

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144. Don’t repeat
     yourself.
     

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145. Parenthesize to
     avoid ambiguity.
     

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146. x || y && z
     

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147. x || (y && z)
     

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148. Keep the code & its
     comments in sync.
     

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149. # This method does bla bla bla.
     # It returns an array of results.
     def bla_bla_bla
     res = Set.new
     # ...
     res
     end
     

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150. bla_bla_bla[0]
     # => Boom Boom Pow
     bla_bla_bla.uniq
     # => Kaboom!
     

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151. //private instance variable for storing age
     public static int age;
     

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152. //private instance variable for storing age
     public static int age;
     

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153. //private instance variable for storing age
     public static int age;
     

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155. Don’t repeat the code
     in the comments.
     

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156. # increment counter by 1
     counter += 1
     

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157. Don’t comment
     shitty code — fix it.
     

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158. //
     // Dear maintainer:
     //
     // Once you are done trying to 'optimize' this routine,
     // and have realized what a terrible mistake that was,
     // please increment the following counter as a warning
     // to the next guy:
     //
     // total_hours_wasted_here = 42
     //
     

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159. Fuck this
     shit!!!
     

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160. View Slide

161. Style guides
     for
     programming languages
     

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162. Python
     

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163. PEP-8
     http://legacy.python.org/dev/peps/pep-0008/
     

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164. Java
     

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165. Sun Style Guide
     http://www.oracle.com/technetwork/java/codeconvtoc-136057.html
     

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166. Google Style Guide
     https://google-styleguide.googlecode.com/svn/trunk/javaguide.html
     

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167. Go
     

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168. Effective Go
     https://golang.org/doc/effective_go.html
     

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169. gofmt
     

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171. StandardJS
     https://standardjs.com/
     

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173. PHP FIG Coding Style
     Guide
     http://www.php-fig.org/psr/psr-1/
     http://www.php-fig.org/psr/psr-2/
     

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174. View Slide

175. Ruby Style Guide
     https://rubystyle.guide
     

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176. View Slide

177. Clojure Style Guide
     https://guide.clojure.style
     

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178. Languages are
     always evolving
     

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179. Good style practices
     are evolving as well
     

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180. { :batman => 'Bruce',
     :superman => 'Clark',
     :zorro => 'Diego',
     :catwoman => 'Selina' }
     

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181. { batman: 'Bruce',
     superman: 'Clark',
     zorro: 'Diego',
     catwoman: 'Selina' }
     

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182. Style consistency is of
     paramount importance
     

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183. Community
     Personal Project
     Company
     

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184. Community
     Project
     Company
     

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185. Style separates
     the good from
     the great
     

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186. Felina
     

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187. One more thing…
     

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188. View Slide