I'；我是编程新手，想知道如何使用ruby创建计算器

这是我当前的计算器代码，但我不知道如何让这两个数字执行这个操作

#calculator
#ask the user for the first number
puts "Please select your first number"
#store num_1 inside a variable
num_1 = gets.chomp.to_i
#spit back the number
puts "#{num_1}"
#ask the user what order of operation they want to use
puts "would you like to add, subtract, multiply, or divide this number?"
#store the order of operation inside a variable
operation = gets.chomp.to_i
#ask the user for a second number
puts "please select a second number to #{operation}"
#store num_2 inside a variable
num_2 = gets.chomp.to_i
#perform the task and spit out a number
answer = num_1 operation num_2
#spit out the number
puts "your answer for #{num_1} #{operation} #{num_2} = #{answer}"

answer = num_1.public_send operation, num_2

---

你快到了。在您的情况下，您需要调用

public\u send

方法来执行所需的操作

#calculator
#ask the user for the first number
puts "Please select your first number"
#store num_1 inside a variable
num_1 = gets.chomp.to_i
#spit back the number
puts "#{num_1}"
#ask the user what order of operation they want to use
puts "would you like to add, subtract, multiply, or divide this number?"
#store the order of operation inside a variable
operation = gets.chomp.to_i
#ask the user for a second number
puts "please select a second number to #{operation}"
#store num_2 inside a variable
num_2 = gets.chomp.to_i
#perform the task and spit out a number
answer = num_1 operation num_2
#spit out the number
puts "your answer for #{num_1} #{operation} #{num_2} = #{answer}"

answer = num_1.public_send operation, num_2

注意：

operation=gets.chomp.to_i

应该是

operation=gets.chomp

根据您的代码，加、减、乘或除将分别为

+

、

-

、

*

和

/

。现在，当您使用

gest

方法将这些作为输入时，您将在咀嚼后获得

'+'

，

'-'

等。现在，根据文档，如果对那些

“+”

、

“-”

等调用

String#to_i

方法

如果

str

开头没有有效数字，则返回

0

了解