未定義的局部變量或方法'停止」主：對象（NameError）

Question

當我試圖做一個循環我的代碼，它突然問我這個：

未定義的局部變量或方法`停'for main：Object（NameError）。

如何解決此錯誤？

loop do 
    puts "Hello. I am a calculator. Please tell me your name." 
    name = gets 
    puts "Hi #{name}. Enter 1 to add, 2 to multiply, 3 to subtract, and 4 to divide." 
    z = gets.chomp.to_i 

    def addition 
    puts "Please enter your first number" 
    a = gets.chomp.to_i 
    puts "Please enter your second number" 
    b = gets.chomp.to_i 
    puts a+b 
    end 

    def multiply 
    puts "Please enter your first number" 
    c = gets.chomp.to_i 
    puts "Please enter your second number" 
    d = gets.chomp.to_i 
    puts c*d 
    end 

    def subtract 
    puts "Please enter your first number" 
    e = gets.chomp.to_i 
    puts "Please enter your second number" 
    f = gets.chomp.to_i 
    puts e-f 
    end 

    def divide 
    puts "Please enter your first number" 
    h = gets.chomp.to_i 
    puts "Please enter your second number" 
    g = gets.chomp.to_i 
    puts h/g 
    end 

    if z == 1 
    puts addition 
    elsif z == 2 
    puts multiply 
    elsif z == 3 
    puts subtract 
    elsif z == 4 
    puts divide 
    end 

    puts "Would you like to calculate something else or stop?" 
    choice = gets.chomp.to_s 

    if choice == stop 
    break 
    end 
end 

Answer 1

的問題是，你有這樣的：

if choice == stop 

我想你的意思是使用：

if choice == 'stop'