Question

给出以下代码：

STARTUPINFO

在class Person attr_accessor :first_name, :last_name @@people = [] def initialize(first_name,last_name) @first_name = first_name @last_name = last_name @@people.push(self) end def self.search(last_name) @last_name = last_name #accept a `last_name` parameter @@people.select { |person| person.last_name } #return a collection of matching instances end #have a `to_s` method to return a formatted string of the person's name def to_s #return a formatted string as `first_name(space)last_name` end end p1 = Person.new("John", "Smith") p2 = Person.new("John", "Doe") p3 = Person.new("Jane", "Smith") p4 = Person.new("Cool", "Dude") puts Person.search("Smith") # Should print out # => John Smith # => Jane Smith位下返回输出需要做什么？我可以让它返回对象id：

Should print out

我看到的一个问题，即使不知道每个内容是什么：应该只返回两个值。很明显，搜索部分也是错误的。

我应该怎么做呢？

Answer 1

    class Person
      attr_accessor :first_name, :last_name
      @@people = []

      def initialize(first_name,last_name)
       @first_name = first_name
       @last_name = last_name
       @@people.push(self)
      end

      def self.search(last_name)
       @@people.select { |person| person.last_name == last_name }
       #return a collection of matching instances
      end

      #have a `to_s` method to return a formatted string of the persons name
      def to_s
        "#{self.first_name} #{self.last_name}"
      end
    end

    p1 = Person.new("John", "Smith")
    p2 = Person.new("John", "Doe")
    p3 = Person.new("Jane", "Smith")
    p4 = Person.new("Cool", "Dude")

    puts Person.search("Smith").collect(&:to_s)

我已经改变了self.search方法来选择具有相同姓氏的对象，显然是to_s方法+得到的东西。如果您有任何其他问题，请阅读测试并告诉我

Answer 2

在@@ Person上添加条件和maping数组。代码在这里描述：

class Person
  attr_accessor :first_name, :last_name    
  @@people = []

  def initialize(first_name,last_name)
    @first_name = first_name
    @last_name = last_name
    @@people.push(self)
  end

  def self.search(last_name)
    @last_name = last_name #accept a `last_name` parameter
     @people = @@people.select { |person|  person.last_name == @last_name }.map{|p| p.first_name.to_s + ' ' + p.last_name.to_s}

    #return a collection of matching instances
  end

  #have a `to_s` method to return a formatted string of the person's name
  def to_s
    #return a formatted string as `first_name(space)last_name`
  end
end

p1 = Person.new("John", "Smith")
p2 = Person.new("John", "Doe")
p3 = Person.new("Jane", "Smith")
p4 = Person.new("Cool", "Dude")

puts Person.search("Smith")

从ruby中的数组返回对象

2 个答案: