Ruby_notes

Class names in Ruby always start with a capital letter.

some source code demonstrating a class

class Person
  attr_accessor :name, :age, :gender
end

attr stands for "attribute" and accessor roughly means "make these attributes accessible to be set and changed at will.

person_instance = Person.new
person_instance.name = "Robert"
person_instance.age = 52
person_instance.gender = "male"

puts person_instance.name

inheritance
class Pet
  attr_accessor :name, :age, :gender, :color
end

class Cat < Pet
end

class Dog < Pet
  def bark
    puts "woof"
  end
end

class Snake < Pet
  attr_accessor :length
end

a_dog = Dog.new
a_dog.bark

puts a_dog.class  #outputs Dog
puts 2.class      #outputs Fixnum numbers are objects of the Fixnum class
puts "This is a test".length  #outputs 14

puts "foobar".sub('bar', 'foo') #outputs foofoo

.sub only does one substitution at a time, on the first instance of the text to match, whereas gsub does
multiple subsitutions at once.
puts "this is a test".gsub('i','') #outputs ths s a test

#force integers to float
9.to_f / 5
#or
9.0 / 5