Question

Is there a way to execute a line of code only if multiple statements are false?

I have an inventory:

inventory = {
    {"Images/Category 1/pistol1.png", false},
    {"Images/Category 1/machinePistol1.png", false},
    {"Images/Category 2/shotgun1.png", false},
    {"Images/Category 2/assaultRifle1.png", false},
    {"Images/Category 3/sniperRifle1.png", false},
    {"Images/Category 3/rocketLauncher1.png", false}
}

And I’d like to write a function that executes a line of code if all those statements are false, but obviously executes something else if even one of them is true.

Answer 1

You can use a variable, and assume it’s true

local IsEverythingTrue = true

-- the **for** statement is a loop. It will allow us to operate
-- the same way on any number elements in inventory.
-- _,v stands for variables that we are going to read from inventory table
-- we can't do it directly, however; **ipairs** function will prepare it so
-- _ will hold numerical index of each element (1, 2, 3 and so on);
-- we don't use it, though, so I put in a placeholder name
-- v will hold every value, so your two-element table

for _,v in ipairs(inventory) do

    -- if any value of v[2] is false, break
    -- v[2] is equal to inventory[_][2]
    -- if not v[2] can be written as 
    -- *if value of v[2] isn't true*

    if not v[2] then
        -- in this case, after first non-true element has been found
        -- we know that not every one is true, or there is at least one false
        IsEverythingTrue = false
        break -- we don't have to check anything else
    end
end

Then use that variable in expression

if IsEverythingTrue then
    -- do something
else
    -- do something else
end

If you want it to execute with multiple falses, just count them. Add local falseCount = 0 at the beginning, and change break for falseCount = falseCount + 1.