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RUBY & RUBY ON RAILS IDIOMS

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A word on style

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- Soft tabs, two space indent - Lines shorter than 80 characters - No spaces after [( and before )] - Methods: snake_case - Classes/Modules: CamelCase - Constants: SCREAMING_SNAKE_CASE - Space after commas: foo(a, b)

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“Idioms”

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if answer == 42 # ... elsif foo == 'foo' # ... else # ... end

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if answer == 42 then # ... elsif foo == 'foo' then # ... else # ... end

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if answer == 42 then # ... elsif foo == 'foo' then # ... else # ... end

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if !correct # ... end

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unless correct # ... end

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unless correct # ... else # ... end

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unless correct single_line_of_something end

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single_line_of_something unless correct single_line_of_something if correct

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message = if correct "You are right!" else "Sorry, that's wrong." end

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if !flaky_value.nil? # ... end

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if flaky_value # ... end

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if env == :production or env == :development # ... end

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if [:production, :development].include?(env) # ... end

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String(123)

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123.to_s

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123.is_a? String

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123.respond_to? :to_s

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def destroy_universe # ... end destroy_universe def destroy_planet(planet) # ... end destroy_planet(:mars)

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destroy_universe()

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def foo(arg1, arg2) # ... end foo 1, 2

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def foo(options, &block) # ... end foo {}

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def green? # ... end def destroy! # ... end

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def foo(name, options) # ... end foo('bar', {:something => 'else', :answer => 42}) foo('bar', :something => 'else', :answer => 42)

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def foo # ... body return results end

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def foo(arg) return unless arg == 42 # ... body end

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a, b = b, a

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a, b = [1, 2, 3]

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%w(helsinki oulu tampere) # => ["helsinki", "oulu", "tampere"]

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%i(helsinki oulu tampere) # => [:helsinki, :oulu, :tampere]

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%i|helsinki oulu tampere| %i-helsinki oulu tampere-

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the_number ||= complex_calculation

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list = [] dictionary = {}

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class Store class << self def advanced_search # ... end end end

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Struct.new("Point", :x, :y)

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class Point < Struct.new(:x, :y) end origin = Point.new(0,0)

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Point = Struct.new(:x, :y) do def to_s "[#{x}, #{y}]" end end Point.new(0,0).to_s # => "[0, 0]"

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class Parent @@class_var = "parent" def self.print_class_var puts @@class_var end end class Child < Parent @@class_var = "child" end Parent.print_class_var # => "child"

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upcase_chars = [] %w(a b c).each do |char| upcase_chars << char.upcase end Not so great

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%w(a b c).map do |char| char.upcase end Better

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%w(a b c).map { |char| char.upcase } Even better

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%w(a b c).map(&:upcase) Great

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Brand.first.stores.map(&:id) Brand.first.store_ids @active_brands.ids

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def make_it_bigga(string) string.upcase end %w(a b c).map(&method(:make_it_bigga))

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[1, 2, nil, 4].compact.reject(&:odd?).inject(&:+) # => 6

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{:foo => "bar", :baz => 42}.each do |key, value| puts "#{key}: #{value}" end # foo: bar # baz: 42 # => {:foo=>"bar", :baz=>42}

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[[:foo, "bar"], [:baz, 42]].each do |(key, value)| puts "#{key}: #{value}" end # foo: bar # baz: 42 # => {:foo=>"bar", :baz=>42}

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[[:foo, "bar"], [:baz, 42]].each do |(_, value)| puts value end # bar # 42 # => [[:foo, "bar"], [:baz, 42]]

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name == "" name.length == 0 name.empty?

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count == 0 count.zero?

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dangerous rescue nil

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FOLLOW YOUR