Is there a Switch-block equivalent?

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#1

So in C#, there is something called “the switch block”
pretty much a better if elseif elseif elseif elseif else statement.
it goes like this:

//C#
string MyString = "Hello"

switch(MyString)
{
  case "apple":
    Console.WriteLine("First case");
    break;
  case "String":
   Console.WriteLine("Second Case");
   break;
  case "Hello":
   Console.WriteLine("HIIIII");
   break;
  default:
   Console.WriteLine("No matches have been found :(");
   break;
}

i would like to know this, since i don’t want to be typing if, elseif , elseif ,elseif, every time…
the switch block is primarily made to take an object and compare it against other objects, as you can see in the example i provided. if no matches are found it runs default, unless there’s none.
so i wonder if lua has this?
because right now this is what the lua equivalent would look like without using the switch block:

--Lua
local Mystring = "hello"

if Mystring == "apple" then
 print("Case one")
elseif Mystring == "String" then
 print("Case two")
elseif Mystring == "hello" then
 print("HIIIII")
else
 print("No matches have been found :(")
end

for me this is way more to type, but it could just be my lazyness acting up again …
so do you know if a lua equivalent switch block exists?

Thanks in advance!

#2

There’s no direct luau equivalent, but you can always just write modules that can achieve the same functionality. For example,

#3

Yeah, use tables:

local MyString = "Hello"
({
	Apple = function()
		print("Apple")
	end,
	String = function()
		print("String")
	end,
	Hello = function()
		print("Hello")
	end,
})[MyString]()

The default case can be implemented using metatables:

local function switch(tbl)
	local mt = {__index=function() return tbl.default end}
	setmetatable(tbl, mt)
	return tbl
end

local MyString = "abc"

switch({
	Apple = function()
		print("Apple")
	end,
	String = function()
		print("String")
	end,
	Hello = function()
		print("Hello")
	end,
	default = function()
		print("Default")
	end,
})[MyString]()

Thanks for coming to my TED talk, I’m happy to showcase my deep and extensive lua knowledge (not to brag).

#4

I’m stupid. You can also just:

local function switch(val)
	return function(tbl)
		if tbl[val] == nil then
			return tbl.default()
		else
			tbl[val]()
		end
	end
end

local MyString = "abc"

switch(MyString) {
	Hello = function()
		print("Hello")
	end,
	Apple = function()
		print("Apple")
	end,
	String = function()
		print("String")
	end,
	default = function()
		print("Default")
	end
}
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