Table Indexing Problem

Help and Feedback Scripting Support
#1

Hey guys, so I have a problem indexing tables. I’m gonna try my best to explain because this may be a bit confusing.




local t = {g = {h = {f = 2}}}

local function Index(IndexPathway, desiredvalue, MainTable)
	
  --Not sure what to write.
	
end

Index({"g", "h", "f"}, 5, t)

So I have a index pathway. What I want the function to do is index the table called " t " and change the value of " f " automatically. I will just have to give the path and the script will change the value of the last pathwaypoint.

So my path is {"g", "h", "f"}, my last pathwaypoint would be f. Which as you can see is there on table " t ". How would I automatically index the table " t " with this pathway and change the value of " f " in the table " t "

If your still confused I would be happy to answer any questions.

Thanks for reading, any help is greatly appreciated! :slight_smile:

#2

You could probably do something like this:

local t = {g = {h = {f = 2}}}

local function Index(IndexPathway, desiredvalue, MainTable)
    local temp = MainTable
    for Index = 1, #IndexPathway - 1 do
        temp = temp[IndexPathway[Index]]
    end
    temp[IndexPathway[#IndexPathway]] = desiredvalue
end

Index({"g", "h", "f"}, 5, t)
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#3

Thanks, that worked! I’m trying to understand what you did now.

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#4

Hey, so I understand everything in the function except this one line:

    temp[IndexPathway[#IndexPathway]] = desiredvalue

When you set the value of that index to the desired value how does that effect the main table? I mean it works, but I’m not sure why it exactly works. Could you explain?

#5

The for loop gets the table that contains the table around the final index, storing it in temp

So if you had

{g = {h = {f = 2}}}
The for loop would store it in temp
temp = {g = {h = {f = 2}}}
Then it would peel off one layer…
temp = {h = {f = 2}}
…then another
temp = {f = 2}
And at this point it stops, because theres only one index left
If you took off another layer, you would have only a number, 2

You cant set the value of a number and have it effect t, you have to change the value of the table
This is why it stops
(Its a similar concept to if you did
local a = 1
local b = a
b = 2
^This does NOT affect a in any way

This however does
local a = {1}
local b = a
b[1] = 2
)

This is why the loop stops before it peels off the final layer
It takes temp, which at this point is {f = 2}, and then takes the final provided index, “f”, and sets that to the desired value

#6

Ohhhh, that makes a lot more sense. Thanks for the help!

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