Question

我正在尝试通过gets.chomp添加用户输入的总成本，然后将其重新放入函数中，以便打印出函数末尾的总成本。我这样做对吗？

def costs_of_company(hosting, design, phones, total_costs)
  puts "Total costs are as follows: \n"
  puts "Hosting costs $#{hosting}."
  puts "Design would cost $#{design}."
  puts "The cost for 100 Phones would be $#{phones}."
  puts "Total costs are #{total_costs}"
end

puts "Tell me the costs of your company. \n"
puts "hosting \n"
hosting = gets.chomp
puts "design \n"
design = gets.chomp
puts "phones \n"
phones = gets.chomp
total_costs = hosting + design + phones  #I think i am way off here.

costs_of_company(hosting, design, phones)

Answer 1

行total_costs = hosting.to_i + design.to_i + phones.to_i的问题是输入是字符串格式。如果您执行了.to_f

，这将有效

这假设所有输入都是整数。或者，如果要使用小数（浮点数），请使用hosting = gets.chomp.to_i。

此外，您还可以执行design = gets.chomp.to_i，phones = gets.chomp.to_i和.to_i

然而，现在我们进入了一个领域，我们如何知道用户是否给了我们很好的输入？如果输入不是整数，则"hello".to_i == 0的默认行为默认为零，例如Integer()。这对大多数情况都很好。

更复杂的方法是创建一个处理用户输入的函数，以便您可以在一个地方清理所有内容，并处理错误。例如，如果您想使用.to_i而不是def get_input while true begin input = gets.chomp.match(/d+/)[0] rescue Exception => e puts "that is not a valid integer. Please try again" else return input end end end，则需要捕获错误，因为对于带有整数的无效输入会抛出异常。下面是使用正则表达式通过异常处理来清理输入的示例。

.myimage { max-width: 100%; height: auto;}



@media only screen 
  and (min-device-width: 320px) 
  and (max-device-width: 480px)
  and (orientation: portrait) {
}

Answer 2

我会用.to_f来追踪美分并将它打印得更漂亮。这是一个调试版本：

def print_money(val)
  format('%.2f',val)
end

def costs_of_company(hosting, design, phones)
  puts "Total costs are as follows: \n"
  puts "Hosting costs $#{print_money(hosting)}."
  puts "Design would cost $#{print_money(design)}."
  puts "The cost for 100 Phones would be $#{print_money(phones)}."
  total_costs = hosting + design + phones
  puts "Total costs are $#{print_money(total_costs)}"
end

puts "Tell me the costs of your company. \n"
puts "hosting \n"
hosting = gets.chomp.to_f
puts "design \n"
design = gets.chomp.to_f
puts "phones \n"
phones = gets.chomp.to_f

costs_of_company(hosting, design, phones)

如何将变量打印回我的函数？

2 个答案: