Editing Lua (section)

=== Syntax ===
The classic [["Hello, World!" program]] can be written as follows, with or without parentheses:<ref>{{cite web |url=https://www.lua.org/pil/1.html |title=Programming in Lua : 1}}</ref>{{efn|Syntactic sugar, a table construct or literal string following an identifier is a valid function call.<ref>{{cite web |url=https://www.lua.org/manual/5.0/manual.html#2.5.7 |title=Lua 5.0 Reference Manual, 2.5.7, Function Calls}}</ref>}}
<syntaxhighlight lang="lua">
print("Hello, World!")
</syntaxhighlight>
<syntaxhighlight lang="lua">
print "Hello, World!"
</syntaxhighlight>

The declaration of a variable, without a value.
<syntaxhighlight lang="lua">
local variable
</syntaxhighlight>

The declaration of a variable with a value of 10.
<syntaxhighlight lang="lua">
local students = 10
</syntaxhighlight>

A [[Comment (computer programming)|comment]] in Lua starts with a double-hyphen and runs to the end of the line, similar to [[Ada (programming language)|Ada]], [[Eiffel (programming language)|Eiffel]], [[Haskell]], [[SQL]] and [[VHDL]]. Multi-line strings and comments are marked with double square brackets.
<syntaxhighlight lang="lua">
-- Single line comment
--[[
Multi-line comment
--]]
</syntaxhighlight>

{{anchor|Factorial example}}The [[factorial]] function is implemented in this example:<!-- referred to elsewhere in this article -->
<syntaxhighlight lang="lua">
function factorial(n)
  local x = 1
  for i = 2, n do
    x = x * i
  end
  return x
end
</syntaxhighlight>