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Programming in Lua | ![]() |
Part I. The Language Chapter 1. Getting Started |
To keep with the tradition,
our first program in Lua just prints "Hello World"
:
print("Hello World")If you are using the stand-alone Lua interpreter, all you have to do to run your first program is to call the interpreter (usually named
lua
) with the name of the text file that contains
your program.
For instance,
if you write the above program in a file hello.lua
,
the following command should run it:
prompt> lua hello.lua
As a slightly more complex example, the following program defines a function to compute the factorial of a given number, asks the user for a number, and prints its factorial:
-- defines a factorial function function fact (n) if n == 0 then return 1 else return n * fact(n-1) end end print("enter a number:") a = io.read("*number") -- read a number print(fact(a))
If you are using Lua embedded in an application,
such as CGILua or IUPLua,
you may need to refer to the application manual (or to a "local guru")
to learn how to run your programs.
Nevertheless, Lua is still the same language;
most things that we will see here are valid regardless of how
you are using Lua.
For a start, we recommend that you use the stand-alone interpreter
(that is, the lua
executable)
to run your first examples and experiments.
Copyright © 2003-2004 Roberto Ierusalimschy. All rights reserved. |
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