io.read（）不起作用

Question

我刚刚开始研究一个非常基本的计算器程序，并且它可以正常工作，我无法在程序完成计算后保持程序打开。 io.read（）似乎不起作用。我的代码如下：

promptmethod = "Would you like to use addition, subtraction, multiplication, or           division?"
promptnumber1 = "Enter a number:"
promptnumber2 = "Enter another number:"
anotherprompt = "Would you like to make another calculation?"

print(promptmethod)
usermethod = io.read("*line")
print(promptnumber1)
number1 = io.read("*number")
print(promptnumber2)
number2 = io.read("*number")

if usermethod == "addition" then
answer = number1 + number2
stringanswer = "Your calculation is " .. number1 .. " + " .. number2 .. " = " .. answer
elseif usermethod == "subtraction" then
answer = number1 - number2
stringanswer = "Your calculation is " .. number1 .. " - " .. number2 .. " = " .. answer
elseif usermethod == "multiplication" then
answer = number1 * number2
stringanswer = "Your calculation is " .. number1 .. " × " .. number2 .. " = " .. answer
elseif usermethod == "division" then
answer = number1 / number2
stringanswer = "Your calculation is " .. number1 .. " ÷ " .. number2 .. " = " .. answer
else
error("Invalid operation or values.")
end

print(stringanswer)

io.read()

有谁知道为什么会这样？谢谢！

Answer 1

一个更简单的例子：

io.read('*number')
io.read()

问题是read('*number')在数字后面没有使用换行符。由于它仍然位于输入流上，因此当您调用io.read（默认为读取一行）时，它会立即返回。

要解决此问题，请再次拨打io.read。