Question

我想通过调用类方法将实例的名称存储在数组中。

当我尝试时，它返回整个实例。当我放object_id时，它返回我的对象的整数标识符。我想要一个数组中实例的名称，稍后我想要用last_name对对象进行排序。

我试过了：

class Person
    attr_accessor :name, :years, :height, :work, :last_name
    @@people=[]
    def initialize(name)
        @name=name
        @@people << self #WHAT TO TYPE HERE???
    end

    def <=> (other_person)  # to compare two people, use last names
      self.last_name <=> other_person.last_name
    end

    def self.number_of_instances
        return @@people
    end

end                
mike=Person.new("michael")
mike.years=45
mike.height=141
mike.work="singer"
mike.last_name="zux"

bob=Person.new("boby")
bob.years=29
bob.height=150
bob.work="soldier"
bob.last_name="awax"

steven=Person.new("stephan")
steven.years=24
steven.height=179
steven.work="painter"
steven.last_name="sigal"

elena=Person.new("eli")
elena.years=20
elena.height=171
elena.work="menager"
elena.last_name="betany"
a= Person.number_of_instances

sorted_names= a.sort!{|first,second| first<=>second }
p sorted_names

预期输出应按其last_name：

的字母顺序排序

[bob, elena, steven, mike]

有没有办法存储我分配给整个对象的名称，如bob，elena，steven，mike？

Answer 1

如果要将名称放在数组中，则只需将名称放在数组中：

@@people << name

Answer 2

class Person
  attr_accessor :name, :last_name
  def initialize(name)
    @name = name
    @last_name = ""
  end
end

class Team
  attr_accessor :team
  def initialize
    @team = []
  end

  def <<(person)
    team.push(person)
  end

  def people_by_last_name

    team.sort_by { |person| person.last_name }.map(&:name)
  end
end
team = Team.new
person = Person.new("Mark")
person.last_name = "Davids"
team << person

person = Person.new("John")
person.last_name = "Stephenson"
team << person

puts team.people_by_last_name

如何获取对象的名称

2 个答案: