基本Lua循环不能正常工作

Question

基本上，我有一个计算器，你可以选择除法，乘法，正负。我刚刚学会了如何循环程序。但是循环并没有正常工作。

print("Please choose the way to use the calculator")
print("[1] Plus [2] Minus [3] Division [4] Multiply")

restart = 1

x = tonumber(io.read())

while restart == 1 do

if x == 1 then
    print("Please write the first number to add up")
    n1 = tonumber(io.read())
    print("Please write the second number to add up")
    n2 = tonumber(io.read())
    print(n1 .. "+" .. n2 .. "=" .. n1+n2)
elseif x == 2 then
    print("Please write the first number to subtract")
    n1 = tonumber(io.read())
    print("Please write the second number to subtract")
    n2 = tonumber(io.read())
    print(n1 .. "-" .. n2 .. "=" .. n1-n2)
elseif x == 3 then
    restart = 0
    print("Please write the first number to divide")
    n1 = tonumber(io.read())
    print("Please write the second number to divide")
    n2 = tonumber(io.read())
    print(n1 .. "/" .. n2 .. "=" .. n1/n2)
elseif x == 4 then
    print("Please write the first number to multiply")
    n1 = tonumber(io.read())
    print("Please write the second number to multiply")
    n2 = tonumber(io.read())
    print(n1 .. "*" .. n2 .. "=" .. n1*n2)
end
end

所以，基本上，如果你选择负值，然后放进10-2。它应该起作用的。但问题是，只有负部分保持循环。它并不要求你选择一种繁衍方式。我怎么才能解决这个问题？

我想让它为你做这个方程，然后循环到开头。

Answer 1

你可以把这个替换一下：

print("Please choose the way to use the calculator")
print("[1] Plus [2] Minus [3] Division [4] Multiply")

restart = 1

x = tonumber(io.read())

while restart == 1 do

通过这一点：

restart = 1

while restart == 1 do

print("Please choose the way to use the calculator")
print("[1] Plus [2] Minus [3] Division [4] Multiply")

x = tonumber(io.read())

另外，由于您正在学习Lua，这里有一种方法可以重构此代码(适当地使用本地语言等)：

local get_operands = function(s)
  print("Please write the first number to " .. s)
  local n1 = io.read("*n")
  print("Please write the second number to " .. s)
  local n2 = io.read("*n")
  return n1, n2
end

while true do

  print("Please choose the way to use the calculator")
  print("[1] Plus [2] Minus [3] Division [4] Multiply")

  local x = io.read("*n")

  if x == 1 then
      local n1, n2 = get_operands("add up")
      print(n1 .. "+" .. n2 .. "=" .. n1+n2)
  elseif x == 2 then
      local n1, n2 = get_operands("subtract")
      print(n1 .. "-" .. n2 .. "=" .. n1-n2)
  elseif x == 3 then
      local n1, n2 = get_operands("divide")
      print(n1 .. "/" .. n2 .. "=" .. n1/n2)
      break
  elseif x == 4 then
      local n1, n2 = get_operands("multiply")
      print(n1 .. "*" .. n2 .. "=" .. n1*n2)
  end

end

Answer 2

你不需要把输入放进你的循环里吗？

x = tonumber(io.read())

while restart == 1 do

应该是

while restart == 1 do

x = tonumber(io.read())

Answer 3

在循环之外设置x，这样它就不会改变。将x=输入放入循环中，这样每次迭代都会重新读取它。