CODEWITHSUNDEEP
lua
user8725115
user8725115

Reputation:

If statement in Lua

i'm trying to do simplest of things:

however current code just prints first message 2 times and exits: 

print("welcome. you have 2 options: play or leave. choose.")
input = io.read()

if input == "play" then
print("let's play")
end

if input == "leave" then
print("bye")
end

if input ~= "play" or "leave" then
print("welcome. you have 2 options: play or leave. choose.")
end

what is wrong here? any help appreciated, thanks

Upvotes: 3

Views: 2238

Answers (4)

yonexsp
yonexsp

Reputation: 11

You need a loop, as you can see this while here is saying, if the input isn't exit, redo the code, and the else means that it will check for the if, the elseif, then finally, the else.

print("welcome. you have 2 options: play or leave. choose.")

while input ~= "exit" do
     input = io.read()
     if input == "play" then
         print("let's play")
     elseif input == "leave" then
         print("bye")
     else
         print("welcome. you have 2 options: play or leave. choose.")
     end
end

Upvotes: 1

lhf
lhf

Reputation: 72422

The usual idiom is

if input == "play" then
   print("let's play")
elseif input == "leave" then
   print("bye")
else
   print("welcome. you have 2 options: play or leave. choose.")
end

but you probably need a loop as suggested by @luther.

Upvotes: 0

luther
luther

Reputation: 5564

An if statement will only execute once. It doesn't jump to other parts of the program. To do that you need to wrap your input code in a while loop and break out when you get a valid response:

while true do
  print("welcome. you have 2 options: play or leave. choose.")
  local input = io.read()

  if input == "play" then
    print("let's play")
    break
  elseif input == "leave" then
    print("bye")
    break
  end

end

Read more about loops here.

Upvotes: 4

Oka
Oka

Reputation: 26385

The line if input ~= "play" or "leave" then is evaluated as:

if (input ~= "play") or "leave" then

The string "leave", or any string for that matter, is considered a truthy value.

You need to compare both strings, using and:

if input ~= "play" and input ~= "leave" then
    print("welcome. you have 2 options: play or leave. choose.")
end

Upvotes: 1

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