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How do I check if an instance's parent exists?

Asked by

greeenblox 28

4 years ago

Edited 4 years ago

Hello! I have been trying to make a raycasting gun that checks if it hit a character or the character's held tools. So far I could not find anything about this.

My code:

if hit then
        if hit.Parent:FindFirstChild("Humanoid") or hit.Parent.Parent:FindFirstChild("Humanoid") or hit.Parent.Parent.Parent:FindFirstChild("Humanoid") then
            if hit.Parent.Humanoid.Health > 0 then
                hit.Parent.Humanoid.Health = hit.Parent.Humanoid.Health - 10
            end
        end
    end

Why am I trying to see if it hit any of a character's tools?

I want the player to be able to shoot the other player ignoring if the slight part of another gun is blocking it.

How my Tool looks Image/Picture

Error(s)/Stacktrace

12:25:06.349 - ServerScriptService.ServerGun:21: attempt to index field 'Parent' (a nil value)
12:25:06.350 - Stack Begin
12:25:06.350 - Script 'ServerScriptService.ServerGun', Line 21
12:25:06.350 - Stack End

Answer/What I did to solve it: https://pastebin.com/raw/cd2RC2gy

2 answers

Answered by

RAFA1608 543

4 years ago

Edited 4 years ago

try checking if it isnt nil (nil = nothing, nothingness.) check if something isnt nil by the code below:

if part then
    print("it exists!")
end

alternatively:

if part ~= nil then
    print("it exists (too)!")
end

if hit then
    if hit.Parent then
        local hum = hit.Parent:FindFirstChild("Humanoid") or hit.Parent.Parent:FindFirstChild("Humanoid")  or hit.Parent.Parent.Parent:FindFirstChild("Humanoid") 
            if hum then
                if hum.Health > 0 then
                    hum.Health = hum.Health - 10
                end
        end
    end
end

hope that helped

I tried adding ~= nil to all of the 'or' checks, it did not work. greeenblox 28 — 4y

no, the thing is, there isnt a parent for the instance hit RAFA1608 543 — 4y

Yeah, that is the problem, if there is no instance it will just error thus creating a massive amount of errors in a full game. Although, I did try something similar and it worked. You apparently cannot try to match FindFirstChild() with nil, so I got around that. I will mark your question as an answer as it partially worked after I extended it, thank you for the solution! greeenblox 28 — 4y

For anyone looking for what I did, here you go: https://pastebin.com/raw/cd2RC2gy greeenblox 28 — 4y

Answered by

PhantomVisual 992

4 years ago

Your code checks if the part hit is correct, but gets the wrong humanoid.

if (hit) then
    local humanoid = hit.Parent:FindFirstChildOfClass("Humanoid") or hit.Parent.Parent:FindFirstChildOfClass("Humanoid")
    if (humanoid) then
        hit.Parent.Humanoid:TakeDamage(10)
        --we don't know if it's the second parent or not
        --which means it'll error if it hits a hat or tool
    end
end

Correction

if (hit) then
    local humanoid = hit.Parent:FindFirstChildOfClass("Humanoid") or hit.Parent.Parent:FindFirstChildOfClass("Humanoid")
    if (humanoid) and (humanoid.Health > 0) then
        humanoid:TakeDamage(10)
        --we know for sure the humanoid exists
        --which means errors aren't possible unless
        --hit's parent is nil
    end
end

As you can see, the var humanoid checks if the parent of the part is the character and looks for the humanoid. The or is used to check the second parent (incase the raycast hits tools or hats).

Note: Humanoid:TakeDamage() will not damage the humanoid if they have a forcefield. Subtracting the health will damage unless their health is inf.

Thanks for providing this answer! greeenblox 28 — 4y

How do I check if an instance's parent exists?

2 answers

Correction

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