Alena's superb Solar_system

Solar_system.rb

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+class Planet
+  attr_reader :name, :position, :type, :moons, :rings, :orbit, :distance_from_the_sun
+  # initializes attributes of each instance of a planet
+  def initialize(planet_hash)
+    @name = planet_hash[:name]
+    @position = planet_hash[:position]
+    @moons = planet_hash[:moons]
+    @type = planet_hash[:type]
+    @rings = planet_hash[:rings]
+    @orbit = planet_hash[:orbit]
+    @distance_from_the_sun = planet_hash[:distance]
+  end
+  # prints information about a specific planet
+  def print_info
+    puts "Here are some basic facts about #{@name}: \nIt has #{@moons} moon(s)."
+    puts "It is an #{@position}, #{@type} type planet. It has #{@rings}."
+    puts "It's solar orbit period is #{@orbit} Earth days."
+    puts "And it's distance from the sun is #{@distance_from_the_sun} million km."
+  end
+  # calculates distance between planets
+  # .abs makes the value absolute (no neg numbers)
+  def distance_from(planet_2)
+    (@distance_from_the_sun - planet_2.distance_from_the_sun).abs
+  end
+end
+
+# array of hashes that are initialized as instances of Planet class
+planet_array = [
+  Planet.new(
+  { name: "Mercury",
+    position: "inner",
+    moons: 0,
+    type: "terrestrial",
+    rings: "no rings",
+    orbit: 88,
+    distance: 58
+  }),
+  Planet.new(
+  {
+    name: "Venus",
+    position: "inner",
+    moons: 0,
+    type: "terrestrial",
+    rings: "no rings",
+    orbit: 225,
+    distance: 108
+  }),
+  Planet.new(
+  {
+    name: "Earth",
+    position: "inner",
+    moons: 1,
+    type: "terrestrial",
+    rings: "no rings",
+    orbit: 365,
+    distance: 150
+  }),
+  Planet.new(
+  {
+    name: "Mars",
+    position: "inner",
+    moons: 2,
+    type: "terrestrial",
+    rings: "no rings",
+    orbit: 689,
+    distance: 230
+  }),
+  Planet.new({
+    name: "Jupiter",
+    position: "outer",
+    moons: 63,
+    type: "gas giant",
+    rings: "rings",
+    orbit: 4333,
+    distance: 778
+  }),
+  Planet.new({
+    name: "Saturn",
+    position: "outer",
+    moons: 62,
+    type: "gas giant",
+    rings: "rings",
+    orbit: 10759,
+    distance: 1400
+  }),
+  Planet.new({
+    name: "Uranus",
+    position: "outer",
+    moons: 27,
+    type: "ice giant",
+    rings: "rings",
+    orbit: 30689,
+    distance:3000
+  }),
+  Planet.new({
+    name: "Neptune",
+    position: "outer",
+    moons: 14,
+    type: "ice giant",
+    rings: "rings",
+    orbit: 60182,
+    distance: 4500
+  })
+]
+# planet option to choose from for the user
+puts "Welcome to our Planetopedia!"
+puts "These are your planet options:"
+planet_array.length.times { |n| puts "#{n + 1} " + planet_array[n].name }
+
+# asks user to choose a planet
+while true
+  puts "Select the number of the planet you would like to know about: "
+  selection = gets.chomp.to_i
+  # creates an instance of a planet
+  planet = (planet_array[selection - 1])
+  # prints information about a selected planet
+  planet.print_info
+  puts "\nWould you like to continue? y/n"
+  answer = gets.chomp
+  break if answer != "y"
+end
+
+class Solar_System
+  attr_reader :name, :formation_year
+  attr_accessor :planets
+  def initialize(name_input, formation_year_input)
+    @name = name_input
+    @planets = []
+    @formation_year = formation_year_input
+  end
+
+  # adding one planet
+  # def add_planet(planet)
+  #   @planets.push(planet)
+  #   puts "you just added #{planet.name}."
+  # end
+
+  #adding a list of planets
+  def add_planets(planet)
+    planet.each do |planet|
+      @planets << planet
+    end
+  end
+
+
+  def local_year(planet)
+    @formation_year / planet.orbit
+  end
+
+end
+
+milky_way = Solar_System.new("Milky Way", 10000000)
+
+milky_way.add_planets(planet_array)
+
+puts "These are the planets inside Milky Way:"
+milky_way.planets.length.times { |n| puts "#{n + 1} " + milky_way.planets[n].name }
+
+puts "Select the numbers of the planets you would like to compare: "
+puts "First planet: "
+first_choice = gets.chomp.to_i
+puts "Second planet: "
+second_choice = gets.chomp.to_i
+
+# calculates the distance between the first two planets added to the @planets array
+interplanetary_distance = milky_way.planets[first_choice - 1].distance_from(milky_way.planets[second_choice - 1])
+puts "The distance between #{milky_way.planets[first_choice - 1].name} and #{milky_way.planets[second_choice - 1].name} is #{interplanetary_distance} million km."
+
+puts "insert the number of the planet you want to know age of: "
+third_choice = gets.chomp.to_i
+# calculates age of a planet that user selected
+planet_age = milky_way.local_year(milky_way.planets[third_choice - 1])
+puts "The selected planet is #{planet_age} years old."