Question

if File.exist?("restaurant.txt") then
  newfile=File.open("restaurant.txt","r")
  lines=newfile.readlines
  i=0
  while i<lines.size
    item=lines[i]
    i+=1
    quantity=lines[i].to_i
    i+=1
    price=lines[i].to_i
    i+=1
    sub=quantity*price
    puts sub
  end
end

我正在尝试将子值移动到数组

Answer 1

只需创建一个数组并推送值。

array = Array.new

if File.exist?("restaurant.txt") then
    newfile = File.open("restaurant.txt","r") 
    lines = newfile.readlines
    i=0
    while i < lines.size
        item = lines[i]
        i += 1
        quantity = lines[i].to_i
        i += 1
        price = lines[i].to_i
        i += 1
        sub = quantity*price
        #puts sub
        array.push(sub)
    end
    puts array.to_s
end

Answer 2

使用File#readlines，数组切片，数组解构和断言前置条件而不是使用if语句，此代码可以简化如下：

#!/usr/bin/env ruby

FILENAME = 'restaurant.txt'

raise "#{FILENAME} does not exist" unless File.file?(FILENAME)

lines = File.readlines(FILENAME).map(&:chomp)

subs = lines.each_slice(3).map do |slice|
  _item, quantity, price = slice
  _item = _item.to_i # _item is unused, but this is here for completeness
  quantity = quantity.to_i
  price = price.to_f
  quantity * price
end

p subs

此外，价格，甚至数量应该是浮点数而不是整数。

如何将局部变量（sub）放在ruby中的数组中

2 个答案: