Question

Noob转向Ruby，并开发了我自己的智能恒温器练习版。我想设置一个初始化的目标温度参数，然后在方法update_temperature中使用当前温度参数！由于某种原因，它引发了一个关于未定义局部变量的错误。

有什么想法吗？

class House
  def initialize(target_temp, max_temp, min_temp)
   @target_temp   = target_temp
   @max_temp      = max_temp
   @min_temp      = min_temp
  end

  def update_temperature!(current_temp)
    @current_temp = current_temp
    if @min_temp < @current_temp && @current_temp < @target_temp
      degrees_ac_off = @target_temp - @current_temp
       puts "The current temperature is #{degrees_ac_off} below the target temperature of #{target_temp}. The air conditioner is off."
    elsif @current_temp < @min_temp
      degrees_below = @min_temp - @current_temp
      puts "The current temperature is #{degrees_below} the minimum desired temperature of #{min_temp}.  The heater is on."
    elsif @target_temp < @current_temp && @current_temp < @max_temp 
      degrees_ac = @current_temp - @target_temp
      puts "The current temperature is #{degrees_high} more than the target temperature of #{target_temp}. The air conditioner is on low."
    else  @max_temp < @current_temp 
     degrees_ac = @current_temp - @target_temp
     puts "The current temperature is #{degrees_ac} more than the target temperature of #{target_temp}. The air conditioner is on high."
     end
   end
end


my_house = House.new(71,75,60)
my_house.update_temperature!(80)

Answer 1

您正在使用调用方法的#{target_temp}，您可以在其前面加上@符号或为它们添加访问器方法。我更喜欢后者。

class House
  attr_accessor :target_temp, :min_temp, :max_temp

Answer 2

您错过了@签名#{target_temp}，#{min_temp}，如下所示。

puts "The current temperature is #{degrees_ac_off} below the target temperature of #{target_temp}. The air conditioner is off."
puts "The current temperature is #{degrees_below} the minimum desired temperature of #{min_temp}. The heater is on."
puts "The current temperature is #{degrees_high} more than the target temperature of #{target_temp}. The air conditioner is on low."
puts "The current temperature is #{degrees_ac} more than the target temperature of #{target_temp}. The air conditioner is on high."

使用以下代码：

class House
  def initialize(target_temp, max_temp, min_temp)
   @target_temp   = target_temp
   @max_temp      = max_temp
   @min_temp      = min_temp
  end

  def update_temperature!(current_temp)
    @current_temp = current_temp
    if @min_temp < @current_temp && @current_temp < @target_temp
      degrees_ac_off = @target_temp - @current_temp
       puts "The current temperature is #{degrees_ac_off} below the target temperature of #{@target_temp}. The air conditioner is off."
    elsif @current_temp < @min_temp
      degrees_below = @min_temp - @current_temp
      puts "The current temperature is #{degrees_below} the minimum desired temperature of #{@min_temp}.  The heater is on."
    elsif @target_temp < @current_temp && @current_temp < @max_temp 
      degrees_high = @current_temp - @target_temp
      puts "The current temperature is #{degrees_high} more than the target temperature of #{@target_temp}. The air conditioner is on low."
    else  @max_temp < @current_temp 
     degrees_ac = @current_temp - @target_temp
     puts "The current temperature is #{degrees_ac} more than the target temperature of #{@target_temp}. The air conditioner is on high."
     end
   end
end


my_house = House.new(71,75,60)
my_house.update_temperature!(80)
#=> The current temperature is 9 more than the target temperature of 71. The air conditioner is on high.

智能家居温控器

2 个答案: