function toboolean()

Converts variable to boolean (true or false) value (the only type usable in conditions).

boolean toboolean(variable)

Parameters

• mixed variable will be converted to boolean value.

Return value

Falsy values are:

• number 0
• boolean false
• string ""
• table {}

Anything else converts to true.

Usage

local answer = 42
if toboolean(answer) then
  log("42 is true!")
else
  log("42 is false!")
end

To use inverse conversion (boolean to number) use 'x and 1 or 0' idiom:

local x = true
logf("x is %d", x and 1 or 0)

See also

Lua system's tonumber() and tostring() functions.