Tables and "for" statements

[pgimeno]

Sounds like you need help about the basics of Lua. Here's a book:

https://www.lua.org/pil/contents.html

Scroll down to "Numeric FOR" (section 4.3.4) and "Generic FOR" (section 4.3.5).

[sphyrth]

Suppose this:

Code: Select all

my_table = { 'cat', 'dog', 'mouse', }

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i returns the indexes of each item... namely 1 through 3.
v returns 'cat', 'dog', and 'mouse' for each cycle depending on their index.

[zorg]

Suppose this:

Code: Select all

my_table = { 'cat', 'dog', 'mouse', }
for i,v in pairs(my_table) do
  -- do stuff for each item's index and/or value
end

i returns the indexes of each item... namely 1 through 3.
v returns 'cat', 'dog', and 'mouse' for each cycle depending on their index.

A few things; for a table like that, with (implicit) numeric keys and no gaps, ipairs is way better, because it will be iterated on in order.
pairs has no definitive order, and traverses all keys, whatever they may be (except nil, you can't have that as a key).

[Jeeper]

I'm having some difficulty understanding how these statements are defined.

Most of the tutorials I can find just tell you to do something like,

for i, v do

But, they don't tell you why and what that means, they tell you not to worry about it now. I can copy the code, and it works, but if I don't know what I'm defining it doesn't help me out at all.

Anybody got a simple breakdown of for statements?

If someone tells you to not worry and copy it, they are not teaching you anything.