CODEWITHSUNDEEP
luacalculator
user9686940
user9686940

Reputation:

lua calculator not working properly

when i type something else than + - * or / it still prints everything out only in the end it says "invalid"

print("+-*/?")
method = io.read()
if method == "+" or "-" or "*" or "/" then
  print("type a number")
  num1 = io.read()
  print("type another number")
  num2 = io.read()
elseif method ~= "+" or "-" or "*" or "/" then
  print("invalid")
end

if method == "+" then
  plusnum = num1 + num2
  print(plusnum)
elseif method == "-" then
  minusnum = num1 - num2
  print(minusnum)
elseif method == "*" then
  timesnum = num1 * num2
  print(timesnum)
elseif method == "/" then
  percentnum = num1 / num2
  print(percentnum)
end

Upvotes: 1

Views: 82

Answers (1)

Piglet
Piglet

Reputation: 28950

Your mistake is in the following line:

if method == "+" or "-" or "*" or "/" then

From Lua 5.3 Reference Manual 3.4.5 Logical Operators

The logical operators in Lua are and, or, and not. Like the control structures (see §3.3.4), all logical operators consider both false and nil as false and anything else as true.

So no matter what method is, the condition of your if statement will always evaluate to true as you're oring at least one true value which results in true.

As Egor already mentioned you have to use:

if method == "+" or method == "-" or method == "*" or method == "/" then

Upvotes: 1

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