Ruby - Strings"a string"
| 'a string'
| “Concate” + “nation”
| “#{concate}#{nation}”
| astring.length
| astring.empty?
| "a,b,c".split(',')
| Result: [a,b,c] |
Single quotes string, auto escape characters. Ruby - Arrayfoo = [a,b,c,d]
| Used for all examples below | foo[n]
| foo.first, foo.second
| foo.length
| foo.last == foo[-1]
| foo.empty?
| foo.include?(x)
| foo.sort[!]
| foo.shuffle[!]
| foo.reverse[!]
| foo.push(x) or foo << x
| foo.join(",")
| Result: "a, b, c, d" | foo[0..2]
| Result: [a,b,c] | foo[1..-1]
| Result: [b,c,d] | ('a'..'d').to_a == foo
|
Ruby - Block3.times { puts "foo" }
| Inline Block | (1..5).each do |i|
puts 2 * i
end
| Multi Line Block | %w[A B C].map { |char| char.downcase }
| %w[A B C].map(&:downcase)
|
The last 2 lines result in an array of ["a", "b", "c"]. The %w creates an array of string. The last one is a weird Ruby shortcut. | | Ruby - Conditionalsputs "string is not empty" if !astring.empty?
puts "string is not empty" unless astring.empty?
if <expression>
...
else
...
end if
|
Ruby - Hash + Symbolfoo = { "name" => "John", "id" => "JH" }
| foo["name"]
| "John" | foo = { name: "John", id: "JH" }
| foo[:id]
| "JH" | foo.each do |key, value|
puts "#{key.inspect} - #{value.inspect}"
end
| :name - "John"
:id - "JH" |
| | Ruby - Objectsanobject.nil?
| True or False | anobject.to_s
| To String |
Ruby - Classmodule BunchOfMethods
def moduleMethod1
...
end
def moduleMethod2
...
end
end
class MyClass < MySuperClass
attr_accessor :attributeA, :attributeB
def initialize(attributes = {})
@attributeA = attributes[:attributeA]
@attributeB = attributes[:attributeB]
end
def NiceString
"#{@attributeA} #{@attributeA}"
end
end
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