Question - How to avoid comparing nil with a number crashes

[Soandso2]

So, my main loop starts like this:

while true do
    if me.Combat() and target() then
        if not stopBellow and target.PctHPs() < 90 and me.AltAbilityReady("Boastful Bellow")() and target.Buff("Boastful Bellow L").ID() == nil then

But it used to start like this:

while true do
    if me.Combat() and target() and target.PctHPs() < 90 then
        if not stopBellow and me.AltAbilityReady("Boastful Bellow")() and target.Buff("Boastful Bellow L").ID() == nil then

The second version crashed multiple times due to "compare nil with a number", in the second if-statement. But after having changed it to the first version... no more crashes.
The "compare nil with a number" error occurs when the target has died and target.PctHPs() result in nil instead of it's current HP.

First of all, what is wrong with the second version of the code?

And is there a way to prevent "compare number with nil" if the target dies before the script actually tries to evaluate the condition?

EDIT: Forgot to mention that me and target in the code are shortened versions of mq.TLO.Me and mq.TLO.Target etc. The Lua WORKS, I am just showing the parts that sometimes crash.

 

[KingArthur]

math.floor(target.PctHPs() or 0)

 

[Soandso2]

math.floor(target.PctHPs() or 0)

Aaaaah, of course! Many thanks!

 

[grimmier]

always try to assign a default fallback incase of a nil value. you can get these especially when zoning

 

[Soandso2]

always try to assign a default fallback incase of a nil value. you can get these especially when zoning

Certainly. I just did not know that you could do that. But when I see the solution above I understand how it works. I get nil values every now and then here and there, and will change all code accordingly to this solution.

 

[tegue]

You can also just make a universal nil function to catch anything. Just stick towards the top of the script.

nil function

local function avoidNil(the_check)
  return the_check or 0
end

while true do
    if me.Combat() and target() and avoidNil(target.PctHPs()) < 90 then
        if not stopBellow and me.AltAbilityReady("Boastful Bellow")() and target.Buff("Boastful Bellow L").ID() == nil then