Question

我的程序从文件中加载列表，我试图更改该方法，以便它自动关闭。

我看过Ruby文档the broad stackoverflow answer和this guy's website，但是语法总是不同的，对我来说还没有太大意义。

我的原始负载：

def load_students(filename = "students.csv")
  if filename == nil
    filename = "students.csv"
  elsif filename == ''
    filename = "students.csv"
  end
  file = File.open(filename, "r")
  file.readlines.each do |line|
    name, cohort = line.chomp.split(",")
    add_students(name).to_s
  end
  file.close
  puts "List loaded from #{filename}."
end

我试图自动关闭：

def load_students(filename = "students.csv")
  if filename == nil
    filename = "students.csv"
  elsif filename == ''
    filename = "students.csv"
  end
  open(filename, "r", &block)
  line.each do |line|
    name, cohort = line.chomp.split(",")
    add_students(name).to_s
  end
  puts "List loaded from #{filename}."
end

我正在寻找相同的结果，但无需手动关闭该文件。

我认为这不会有太大的不同，那么自动关闭块的语法如何工作？

Answer 1

File.open(filename, 'r') do |file|
  file.readlines.each do |line|
    name, cohort = line.chomp.split(",")
    add_students(name).to_s
  end
end

我将重构整个代码：

def load_students(filename = "students.csv")
  filename = "students.csv" if filename.to_s.empty?
  File.open(filename, "r") do |file|
    file.readlines.each do |line|
      add_students(line.chomp.split(",").first)
    end
  end
  puts "List loaded from #{filename}."
end

或者，甚至更好的是，如Kimmo Lehto在评论中建议的那样：

def load_students(filename = "students.csv")
  filename = "students.csv" if filename.to_s.empty?
  File.foreach(filename) do |line|
    add_students(line.chomp.split(",").first)
  end
  puts "List loaded from #{filename}."
end

重构我的代码，使文件关闭自动加载一次，请问语法工作？

1 个答案: