如何在Ruby中将磅转换为kg？

Question

当我在Ruby中运行下面的代码时，我收到一条错误消息：ex5.rb:3:in '< main >': undefined local variable or method 'cm' for main:Object < NameError >

我做错了什么？

name = 'Chris Hanson'
height = 60 * cm 
cm = 2.54
weight = 180 % kg 
kg = 2.2
eyes = 'Brown'
teeth = 'White'
hair = 'Black'

puts "Let's talk about #{name}."
puts "He's #{height} cm tall."
puts "He's #{weight} kg heavy."
puts "He's got #{eyes} eyes and #{hair} hair."
puts "His teeth are usually #{teeth} depending on the coffee."

Answer 1

此处的错误不是在使用它们之前声明变量。查看我使用的顺序（'cm'和'kg'变量）：

name = 'Chris Hanson'
cm = 2.54
height = 60 * cm
kg = 2.2
weight = 180 % kg
eyes = 'Brown'
teeth = 'White'
hair = 'Black'

puts "Let's talk about #{name}."
puts "He's #{height} cm tall."
puts "He's #{weight} kg heavy."
puts "He's got #{eyes} eyes and #{hair} hair."
puts "His teeth are usually #{teeth} depending on the coffee."

这似乎工作正常。

Answer 2

Ruby中的变量只能在声明后引用。尝试移动变量＆＃34; height＆＃34;低于＆＃34; cm＆＃34;。同样，你应该放置＆＃34; weight＆＃34;低于＆＃34; kg＆＃34;。