Question

所以我正在ruby中创建一个类，在那里我可以将数据插入文本文件中，然后从中读取，查找，但是我被困在删除以及更新/编辑上。

基本上，我创建了一个名为“ find”的方法，并将其作为“ delete”方法的参考。

def find(keyword="")
  if keyword
    person = People.read_people
    found = person.select do |pip|
      pip.name.downcase.include?(keyword.downcase) ||
        pip.age.downcase.include?(keyword.downcase) ||
        pip.country.downcase.include?(keyword.downcase)
    end
    found.each do |person|
      puts person.name + " | " + person.age + " | " + person.country
    end
  else
    puts "find using a key phrase eg. 'find sam' \n\n"
  end
end


def list
  puts "\nListing People \n\n".upcase
  people = People.read_people
  people.each do |person|
    puts person.name + " | " + person.age + " | " + person.country
  end
end


def delete(keyword="")
  if keyword
    person = People.read_people
    found = person.select do |pip|
      pip.name.downcase.include?(keyword.downcase) ||
        pip.age.downcase.include?(keyword.downcase) ||
        pip.country.downcase.include?(keyword.downcase)
    end
    person.delete(found)
  else
    puts "find using a key phrase eg. 'find josh' \n\n"
  end
end

如您所见，我正在尝试通过名为read_people的类方法从数组中删除提供的关键字（w / c保存在文本文件中）。外观如下：

def self.read_people
  # read the people file
  # return instances of people
  people = []
  if file_usable?
    file = File.new(@@filepath, 'r')
    file.each_line do |line|
      people << People.new.import_line(line.chomp)
    end
    file.close
  end
  return people
end

def import_line(line)
  line_array = line.split("\t")
  @name, @age, @country = line_array
  return self
end

如何解决此问题并通过关键字删除找到的项目？

在此处查看实际代码：https://repl.it/repls/VastWildFact

Answer 1

更改

person.delete(found)

到

person -= found # Equivalent to person = person - found

它应该按照https://ruby-doc.org/core-2.2.0/Array.html#method-i-2D

运行

ary - other_ary → new_ary

返回一个新数组，该数组是原始数组的副本，并删除也出现在other_ary中的所有项目。该顺序保留在原始数组中。

它使用哈希和eql比较元素？效率的方法。

示例：[1，1，2，2，3，3，4，5]-[1，2，4]＃=> [3，3，5]

另一种解决方案是按如下方式使用reject：

person.reject! do |pip|
  pip.name.downcase.include?(keyword.downcase) ||
    pip.age.downcase.include?(keyword.downcase) ||
    pip.country.downcase.include?(keyword.downcase)
end

Answer 2

基本上，您将需要一种看起来像这样的export_people和write_people方法：

def self.export_people(people)
  people.map do |person|
    [person.name, person.age, person.country].join("\t")
  end
end

def self.write_people(people)
  File.new(@@filepath, 'w') do |f|
    f.write(export_people(people))
  end
end

# Usage:
Person.write_people(array_of_people)

使用上面的代码，您将调用modified delete method as detailed in Tarek's answer，然后调用Person.write_people(array_of_people)写回文件。

从Ruby中的类中删除数组

2 个答案: