Progress forwards and backwards through table - lua

Question

first time here on Stack Overflow but definitely have found a lot of useful information here!
Currently I'm trying to figure out how to select the next item, or previous item in a table based on the current selection.
My current table is as follows:
maleSkins = { 7,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,32,33,34,35,
36,37,43,44,45,46,47,48,49,51,52,57,58,59,60,61,66,67,72,73,80,82,83,
84,94,95,96,97,98,99,100,101,102,103,104,105,106,107,108,109,110,111,
112,113,114,115,116,117,118,120,121,122,123,124,125,126,127,128,132,
133,134,135,136,137,142,143,144,146,147,153,154,156,159,160,161,162,
168,170,173,174,175,176,177,179,180,181,182,183,184,185,186,187,188,
189,200,202,203,204,206,210,212,213,217,220,221,222,223,227,228,229,
230,234,235,236,239,240,241,242,247,248,249,250,252,254,258,259,260,261,262 }
femaleSkins = { 9,10,11,12,13,31,38,39,40,41,53,54,55,56,69,76,77,88,89,90,91,92,
93,129,130,131,138,139,140,141,145,148,151,152,157,190,191,192,193,195,
196,197,198,199,201,207,211,214,215,216,218,219,224,225,226,232,233,237,238,243,244,245,246,251,256,257 }
The default selection is "7" in the maleSkins table, and I will use the femaleSkins table when they choose "female" for their gender.
Currently my function call looks like this
function selSkin(button,state)
if button ~= "left" and state ~= "up" then
return
end
if source == createChar.maleButt then
femaleSkin = false
maleSkin = true
elseif source == createChar.femaleButt then
maleSkin = false
femaleSkin = true
end
if source == createChar.nextSkin then
if maleSkin == true then
newModel = table.concat(maleSkins,)
elseif femaleSkin == true then
end
elseif source == createChar.prevSkin then
if maleSkin == true then
elseif femaleSkin == true then
end
end
end
So, inside the "createChar.nextSkin" and "createChar.prevSkin" is where I'm trying to sort through the table based on the current skin, but I'm unsure of how to proceed.
I would love if someone could give me the building blocks to do this, and I will build the rest myself!
(Side note: Predefined variables I will be using to make this happen)
maleSkin = true
femaleSkin = true
curSkin = 7
newModel = nil

Answer 1

First of all welcome to stack overflow :)
A small thing I noticed: you have two variables to store if the character is male or female. This allows for 4 combinations, 2 of which make no sense. You could just as well only use one variable, say, maleSkin and when it's false, then you use the female skin instead. Alternatively, you could just do skinType = 'male' and skinType = 'female' (Lua interns strings, so this is just as fast as comparing integers)
now, unless you plan to have a few millions of skins or more, you can just iterate through the table to find the current skin and then use the previous one.
function skinOffset(skin, skinList, offset)
for i,current_skin in ipairs(skinList) do
if current_skin == skin then
return skinList[i + offset]
else
end
end
Now, to get the next skin you can do skinOffset(curSkin, maleSkins, 1) and for the previous one skinOffset(curSkin, femaleSkins, -1).

Answer 2

Additionally save the table index in a global var.
There are several ways, for instance skinIndex = 1, your code could look like this:
if source == createChar.nextSkin then
newModel = maleSkin and maleSkins[skinIndex + 1] or femaleSkins[skinIndex + 1]
elseif source == createChar.prevSkin then
newModel = maleSkin and maleSkins[skinIndex - 1] or femaleSkins[skinIndex - 1]
end
But you have to beware of skinIndex < 1 or > #maleSkins/#femaleSkins