减去变量

Question

我正在尝试计算由种族决定的年龄，种族和估计的生命长度。但我在这里遇到了一个问题，特别是最后一行代码。有人可以帮忙吗？

puts "What year were you born? "
age = gets
puts age
var1 = age
puts "sorry, i am a slow computer... What year is it?"
year = gets
var2 = "2013"
puts "ok it is" + year + "so you must be"
puts var2 - var1.to_i

Answer 1

你是在正确的轨道，但问题是你没有将var2转换为整数，ruby解释器将其视为一个字符串因此错误。这是正确的代码。

puts "What year were you born? "
age = gets
puts age
var1 = age
puts "sorry, i am a slow computer... What year is it?"
year = gets
var2 = "2013"
puts "ok it is" + year + "so you must be"
puts var2.to_i - var1.to_i

Answer 2

您正尝试从字符串中减去一个整数。这会引发错误。

我认为你正在寻找类似的东西;

puts "What year were you born?"
born = gets.chomp
puts "sorry, i am a slow computer... What year is it?"
date = gets.chomp
age = date.to_i - born.to_i 
puts "ok it is #{date} so you must be #{age}"

Answer 3

在这种情况下，

var2是一个字符串，因为你在一年中都有引号。 只需在var2上使用.to_i，你应该没问题。