在Ruby对象类中创建数组

发布时间：2020-12-17 03:03:23 所属栏目：百科来源：网络整理

导读：我只想编写一个 Ruby脚本(没有rails),其中包含一个包含id数组的类.这是我原来的课程： # define a "Person" class to represent the three expected columnsclass Person # a Person has a first name,last name,and city Struct.new(:first_name,:last_name

我只想编写一个 Ruby脚本(没有rails),其中包含一个包含id数组的类.这是我原来的课程：

# define a "Person" class to represent the three expected columns
class Person <

  # a Person has a first name,last name,and city
  Struct.new(:first_name,:last_name,:city)

  # a method to print out a csv record for the current Person.
  # note that you can easily re-arrange columns here,if desired.
  # also note that this method compensates for blank fields.
  def print_csv_record
    last_name.length==0 ? printf(",") : printf(""%s",",last_name)
    first_name.length==0 ? printf(",first_name)
    city.length==0 ? printf("") : printf(""%s"",city)
    printf("n")
  end
end

现在我想在类中添加一个名为ids的数组,我可以将它包含在Struct.new语句中,如Struct.new(：first_name,：last_name,：city,：ids = Array.new)或创建实例数组变量或任何定义单独的方法或其他东西？

我希望能够做到这样的事情：

p = Person.new
p.last_name = "Jim"
p.first_name = "Plucket"
p.city = "San Diego"

#now add things to the array in the object
p.ids.push("1")
p.ids.push("55")

并遍历数组

p.ids.each do |i|
  puts i
end

解决方法

# define a "Person" class to represent the three expected columns
class Person
 attr_accessor :first_name,:city,:ids
#  Struct.new(:first_name,:ids) #used attr_accessor instead  can be used this too 

def initialize
     self.ids = [] # on object creation initialize this to an array
end
  # a method to print out a csv record for the current Person.
  # note that you can easily re-arrange columns here,if desired.
  # also note that this method compensates for blank fields.
  def print_csv_record
    print last_name.empty? ? "," : ""#{last_name}","
    print first_name.empty? ? "," : ""#{first_name}","
    print city.empty? ? "" : ""#{city}","
    p "n"
  end
end

p = Person.new
p.last_name = ""
p.first_name = "Plucket"
p.city = "San Diego"

#now add things to the array in the object
p.ids.push("1")
p.ids.push("55")

#iterate
p.ids.each do |i|
  puts i
end

（编辑：李大同）

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