How do I delete all contents of a table at once?

[Kasperelo]

As the title says, how can I delete everything in a table at once? When I use

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table.remove(the table I want to delete the content of)

it starts with the last thing added and deletes it way to the start. Help?

[Automatik]

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thetable = {}

[borix134]

This might be what you need:

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for i,v in ipairs(table) do
table.remove(table, i)
end

[Robin]

Generally, you'd want to create a new table.

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mytable = {}

As long as that was the only reference to the old table, it will be garbage collected.

If there is more than one reference to the table you want cleared, I think you could do:

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for k, v in pairs(mytable) do
    mytable[k] = nil
end

... but I'm not too sure, because I keep forgetting what works for "modifying tables while looping over them" and what doesn't, and I'm too lazy to put it to the test.

(Wow, ninja'd twice. I'm slow.)

[raidho36]

You can't delete and add keys in looping a table throuh the iterator. That is, you can, but under such conditions behavior is undefined.

[Kasperelo]

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thetable = {}

Thanks, this worked perfectly!



I feel like an idiot not figuring that out.

[T-Bone]

If you happen to only use numerical indexing, you can just do

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for i = #tab,1,-1 do
    tab[i] = nil
end

This is faster than creating and destroying tables if you need to do it often (like a significant number of times every frame). It's probably not something to worry about unless you actually experience slow-downs.

[bartbes]

You can't delete and add keys in looping a table throuh the iterator. That is, you can, but under such conditions behavior is undefined.

That is not true for next (and therefore pairs), you just can't add, but you can delete, according to the manual:

The behavior of next is undefined if, during the traversal, you assign any value to a non-existent field in the table. You may however modify existing fields. In particular, you may clear existing fields.