What are square brackets ([]) and hashtags (#) used for?
So while looking through morph scripts I found this:
function onTouched(hit)
if hit.Parent:findFirstChild("Humanoid") ~= nil and hit.Parent:findFirstChild("Arm1") == nil then
local g = script.Parent.Parent.Arm1:clone()
g.Parent = hit.Parent
local C = g:GetChildren()
for i=1, #C do
if C[i].className == "Part" then
local W = Instance.new("Weld")
W.Part0 = g.Middle
W.Part1 = C[i]
local CJ = CFrame.new(g.Middle.Position)
local C0 = g.Middle.CFrame:inverse()*CJ
local C1 = C[i].CFrame:inverse()*CJ
W.C0 = C0
W.C1 = C1
W.Parent = g.Middle
end
local Y = Instance.new("Weld")
Y.Part0 = hit.Parent["Left Arm"]
Y.Part1 = g.Middle
Y.C0 = CFrame.new(0, 0, 0)
Y.Parent = Y.Part0
end
local h = g:GetChildren()
for i = 1, # h do
if h[i].className == "Part" then
h[i].Anchored = false
h[i].CanCollide = false
end
end
end
end
script.Parent.Touched:connect(onTouched)
I'd like to know what the # (eg #C) and the square brackets (eg C[i]) mean. Thanks in advance!
2 answers
The Hashtag(#) symbol is used when referring to a quantity of something. i.e
local aTable = {"Hello","Welcome","To","Scripting","Helpers!"}
for i = 1,#aTable do --The for loop executes depending on the number of items in aTable
print(aTable[i]) --This prints the string that corresponds with the item number; i.e. print(aTable[2]) would print, "Welcome"
end
--Output: --Hello --Welcome --To --Scripting --Helpers!
# is used to find the length of a list or a string. It returns a number.
[] are used to either search for a child via a string, or search a list via a number. It returns the object or value.
Brackets:
Just like a dot, but you can use a string, i.e.
workspace.Part -- = workspace["Part"]
Useful if then name of an object has spaces.
--INCORRECT: workspace.The Part --CORRECT workspace["The Part"]
Can also be used to get a value from a table via a number;
local myTable = {"valA", "valB", "valC"}
print(myTable[2]) --valB
print(myTable[3]) --valC
print(myTable[1]) --valA
print(myTable[math.random(1,3)]) --random
If you have a variable for a number, and that variable is changing, you can "loop through" the list;
local myTable = {"valA", "valB", "valC"}
for i = 1,3 do
print(myTable[i])
end
The GetChildren() method returns a table of all the children of an object, so it works the same way.
Number sign:
It's best not to think of it as a hashtag or the pounds symbol, because in Lua it is used as a number sign. When placed before a list, it return the number of that list. It can also be used for strings; it will return the number of characters.
local myTable = {"valA", "valB", "valC"}
local myString = "Hello!"
print(#myTable)
print(#myString)