This document discusses the author's love of Ruby and some of its key qualities, including its simple syntax, object-oriented nature, duck typing, blocks, and open classes. It provides examples of initializing arrays and hashes, defining classes, how everything is an object in Ruby, duck typing without type constraints, using blocks, accepting blocks, and modifying classes in open ways. The author advocates for Ruby but also notes the responsibility that comes with its flexibility.
12. Classes
class Rectangle
attr_accessor :width, :height
def initialize(width, height)
self.width = width
self.height = height
end
def area
width * height
end
end
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13. >> r = Rectangle.new(5, 20)
=> #<Rectangle:0x3691d8 @width=5, @height=20>
>> r.area
=> 100
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14. Qualities
Simple Syntax
Object-Oriented
Duck-Typing
Blocks
Open Classes
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15. Everything is an object
>> 9.succ
=> 10
>> 9.nil?
=> false
>> 9.between? 8, 10
=> true
>> 9.class
=> Fixnum
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16. No Really
>> 9.succ
=> 10
>> 9.nil?
=> false
>> 9.between? 8, 10
=> true Wha?
>> 9.class
=> Fixnum
>> Fixnum.class
=> Class
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17. Ever written something like this?
public void MakeItQuack<T>(T quacker)
where T : ICanQuack
{
quacker.Quack();
}
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18. Really Wanted
public void MakeItQuack<T>(T quacker)
where T can quack
{
quacker.quack();
}
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19. Qualities
Simple Syntax
Object-Oriented
Duck-Typing
Blocks
Open Classes
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24. Type != Class
Behavior/Interaction-Orientation
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25. Qualities
Simple Syntax
Object-Oriented
Duck-Typing
Blocks
Open Classes
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26. Blocks
a = [5, 7, 10, 24]
a.each do |num|
puts num
end
b = a.map do |num|
num * 2
end
puts b.inspect
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27. Accepting Blocks
def five_times
yield 1
yield 2
yield 3
yield 4
yield 5
end
five_times do |num|
puts num
end
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28. Accepting Blocks
def five_times(&block)
block.call(1)
block.call(2)
block.call(3)
block.call(4)
block.call(5)
end
five_times do |num|
puts num
end
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29. Qualities
Simple Syntax
Object-Oriented
Duck-Typing
Blocks
Open Classes
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30. Open Classes
Say goodbye to sealed/virtual/override/argh
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31. def convert(to_convert)
return nil if to_convert.nil?
return to_convert if to_convert.empty?
do_conversion(to_convert)
end
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32. As You Wish
class NilClass
def empty?
true
end
end
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33. def convert(to_convert)
return to_convert if to_convert.empty?
do_conversion(to_convert)
end
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34. Setting Time
current_time = 17
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35. write the code you wish you had
current_time = 5.pm
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36. Then get it working
class Fixnum
def pm
self + 12
end
end
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37. Type != Class (redux)
a = “coreyhaines@gmail.com;me@coreyhaines.com”
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38. Type != Class (redux redux)
a = “coreyhaines@gmail.com;me@coreyhaines.com”
a.extend(EmailAddressList)
puts a.email_addresses.inspect
a.each_address do |address|
Mailer.send_email_to(address)
end
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39. Remember
With great power comes great responsibility
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40. Qualities
Simple Syntax
Object-Oriented
Duck-Typing
Blocks
Open Classes
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41. Qualities
Awesomeness!
Simple Syntax
Object-Oriented
Duck-Typing
Blocks
Open Classes
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