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    Quick Lua Tour

    b83devb83dev Member
    edited February 2012 in Code snippets
    I thought the QuickLuaTour.lua (all credit goes to AGR Wilson) from LuaForWindows might be useful for new users of lua. It also may be useful to quickly look up what a piece of code on the forum is referring to.

    The QuickLuaTour.lua is using the MIT License. Please visit http://mit-license.org/ to read about this license.

    -- QuickLuaTour.lua
    --
    -- A quick tour of the Lua Scripting Language.
    --
    -- Created: May 21, 2008,
    -- Updated: Sept 4th, 2008 Fix typos, minor changes, better formatting.
    -- Author: AGR Wilson
    -- Some more updates and fixes by Dirk Feytons.
    --
    -- To add later? - serialize table, self-executing code, closures, co-routines.
    --

    [==[
    -- First Program.
    -- Classic hello program.
     print("hello")
    ]==],

    [==[
    -- Comments.
    -- Single line comments in Lua start with double hyphen.
    --[[ Multiple line comments start
with double hyphen and two square brackets.
  and end with two square brackets. ]]
 
-- And of course this example produces no
-- output, since it's all comments!
    ]==],

    [==[
    -- Variables.
    -- Variables hold values which have types, variables don't have types.
    a=1
b="abc"
c={}
d=print
 
print(type(a))
print(type(b))
print(type(c))
print(type(d))
    ]==],

    [==[
    -- Variable names.
    -- Variable names consist of letters, digits and underscores.
    -- They cannot start with a digit.
    one_two_3 = 123 -- is valid varable name
 
-- 1_two_3 is not a valid variable name.
    ]==],

    [==[
    -- More Variable names.
    -- The underscore is typically used to start special values
    -- like _VERSION in Lua.
    print(_VERSION)
    -- So don't use variables that start with _,
    -- but a single underscore _ is often used as a
    -- dummy variable.

    ]==],
    [==[
    -- Case Sensitive.
    -- Lua is case sensitive so all variable names & keywords
    -- must be in correct case.
    ab=1
Ab=2
AB=3
print(ab,Ab,AB)
    ]==],
    [==[
    -- Keywords.
    -- Lua reserved words are: and, break, do, else, elseif,
    -- end, false, for, function, if, in, local, nil, not, or,
    -- repeat, return, then, true, until, while.

    -- Keywords cannot be used for variable names,
    -- 'and' is a keyword, but AND is not, so it is a legal variable name.
    AND=3
print(AND)
    ]==],

    [==[
    -- Strings.
    a="single 'quoted' string and double \"quoted\" string inside"
b='single \'quoted\' string and double "quoted" string inside'
c= [[ multiple line
with 'single'
and "double" quoted strings inside.]]
 
print(a)
print(b)
print(c)
    ]==],

    [==[
    -- Assignments.
    -- Multiple assignments are valid.
    -- var1,var2=var3,var4
    a,b,c,d,e = 1, 2, "three", "four", 5
 
print(a,b,c,d,e)
    ]==],
    [==[
    -- More Assignments.
    -- Multiple assignments allows one line to swap two variables.
    print(a,b)
a,b=b,a
print(a,b)
    ]==],
    [==[
    -- Numbers.
    -- Multiple assignment showing different number formats.
    -- Two dots (..) are used to concatenate strings (or a
    -- string and a number).
    a,b,c,d,e = 1, 1.123, 1E9, -123, .0008
print("a="..a, "b="..b, "c="..c, "d="..d, "e="..e)
    ]==],
    [==[
    -- More Output.
    -- More writing output.
    print "Hello from Lua!"
print("Hello from Lua!")
    ]==],
    [==[
    -- More Output.
    -- io.write writes to stdout but without new line.
    io.write("Hello from Lua!")
io.write("Hello from Lua!")
 
-- Use an empty print to write a single new line.
print()
    ]==],

    [==[
    -- Tables.
    -- Simple table creation.
    a={} -- {} creates an empty table
b={1,2,3} -- creates a table containing numbers 1,2,3
c={"a","b","c"} -- creates a table containing strings a,b,c
print(a,b,c) -- tables don't print directly, we'll get back to this!!
    ]==],

    [==[
    -- More Tables.
    -- Associate index style.
    address={} -- empty address
address.Street="Wyman Street"
address.StreetNumber=360
address.AptNumber="2a"
address.City="Watertown"
address.State="Vermont"
address.Country="USA"
 
print(address.StreetNumber, address["AptNumber"])
    ]==],

    [==[
    -- if statement.
    -- Simple if.
    a=1
if a==1 then
    print ("a is one")
end
    ]==],

    [==[
    -- if else statement.
    b="happy"
if b=="sad" then
    print("b is sad")
else
    print("b is not sad")
end
    ]==],

    [==[
    -- if elseif else statement
    c=3
if c==1 then
    print("c is 1")
elseif c==2 then
    print("c is 2")
else
    print("c isn't 1 or 2, c is "..tostring(c))
end
    ]==],

    [==[
    -- Conditional assignment.
    -- value = test and x or y
    a=1
b=(a==1) and "one" or "not one"
print(b)
 
-- is equivalent to
a=1
if a==1 then
    b = "one"
else
    b = "not one"
end
print(b)
    ]==],

    [==[
    -- while statement.
    a=1
while a~=5 do -- Lua uses ~= to mean not equal
    a=a+1
    io.write(a.." ")
end
    ]==],

    [==[
    -- repeat until statement.
    a=0
repeat
    a=a+1
    print(a)
until a==5
    ]==],

    [==[
    -- for statement.
    -- Numeric iteration form.
    -- Count from 1 to 4 by 1.
for a=1,4 do io.write(a) end
 
print()
 
-- Count from 1 to 6 by 3.
for a=1,6,3 do io.write(a) end
    ]==],

    [==[
    -- More for statement.
    -- Sequential iteration form.
    for key,value in pairs({1,2,3,4}) do print(key, value) end
    ]==],

    [==[
    -- Printing tables.
    -- Simple way to print tables.
    a={1,2,3,4,"five","elephant", "mouse"}
 
for i,v in pairs(a) do print(i,v) end
    ]==],

    [==[
    -- break statement.
    -- break is used to exit a loop.
    a=0
while true do
    a=a+1
    if a==10 then
        break
    end
end
 
print(a)
    ]==],

    [==[
    -- Functions.
    -- Define a function without parameters or return value.
function myFirstLuaFunction()
    print("My first lua function was called")
end
 
-- Call myFirstLuaFunction.
myFirstLuaFunction()
    ]==],

    [==[
    -- More functions.
    -- Define a function with a return value.
function mySecondLuaFunction()
    return "string from my second function"
end
 
-- Call function returning a value.
a=mySecondLuaFunction("string")
print(a)
    ]==],

    [==[
    -- More functions.
    -- Define function with multiple parameters and multiple return values.
function myFirstLuaFunctionWithMultipleReturnValues(a,b,c)
    return a,b,c,"My first lua function with multiple return values", 1, true
end
 
a,b,c,d,e,f = myFirstLuaFunctionWithMultipleReturnValues(1,2,"three")
print(a,b,c,d,e,f)
    ]==],

    [==[
    -- Variable scoping and functions.
    -- All variables are global in scope by default.
    b="global"
 
-- To make local variables you must put the keyword 'local' in front.
function myfunc()
    local b=" local variable"
    a="global variable"
    print(a,b)
end
 
myfunc()
print(a,b)
    ]==],

    [==[
    -- Formatted printing.
    -- An implementation of printf.
    function printf(fmt, ...)
    io.write(string.format(fmt, ...))
end
 
printf("Hello %s from %s on %s\n",
       os.getenv"USER" or "there", _VERSION, os.date())
    ]==]

    Likes: strancali, DarkPixel, kamcknig, Platypus, bravcm

    +1 -1 (+5 / -0 )Share on Facebook

    Comments

    • b83devb83dev Member
      edited February 2012
      [==[
      --[[

      Standard Libraries

      Lua has standard built-in libraries for common operations in
      math, string, table, input/output & operating system facilities.

      External Libraries

      Numerous other libraries have been created: sockets, XML, profiling,
      logging, unittests, GUI toolkits, web frameworks, and many more.

      ]]

      ]==],

      [==[
      -- Standard Libraries - math.

      -- Math functions:
      -- math.abs, math.acos, math.asin, math.atan, math.atan2,
      -- math.ceil, math.cos, math.cosh, math.deg, math.exp, math.floor,
      -- math.fmod, math.frexp, math.huge, math.ldexp, math.log, math.log10,
      -- math.max, math.min, math.modf, math.pi, math.pow, math.rad,
      -- math.random, math.randomseed, math.sin, math.sinh, math.sqrt,
      -- math.tan, math.tanh
      print(math.sqrt(9), math.pi)
      ]==],

      [==[
      -- Standard Libraries - string.

      -- String functions:
      -- string.byte, string.char, string.dump, string.find, string.format,
      -- string.gfind, string.gsub, string.len, string.lower, string.match,
      -- string.rep, string.reverse, string.sub, string.upper
      print(string.upper("lower"),string.rep("a",5),string.find("abcde", "cd"))
      ]==],

      [==[
      -- Standard Libraries - table.

      -- Table functions:
      -- table.concat, table.insert, table.maxn, table.remove, table.sort
      a={2}
table.insert(a,3);
table.insert(a,4);
table.sort(a,function(v1,v2) return v1 > v2 end)
for i,v in ipairs(a) do print(i,v) end
      ]==],

      [==[
      -- Standard Libraries - input/output.

      -- IO functions:
      -- io.close , io.flush, io.input, io.lines, io.open, io.output, io.popen,
      -- io.read, io.stderr, io.stdin, io.stdout, io.tmpfile, io.type, io.write,
      -- file:close, file:flush, file:lines ,file:read,
      -- file:seek, file:setvbuf, file:write
             print(io.open("file doesn't exist", "r"))
      ]==],

      [==[
      -- Standard Libraries - operating system facilities.

      -- OS functions:
      -- os.clock, os.date, os.difftime, os.execute, os.exit, os.getenv,
      -- os.remove, os.rename, os.setlocale, os.time, os.tmpname
      print(os.date())
      ]==],

      [==[
      -- External Libraries.
      -- Lua has support for external modules using the 'require' function
      -- INFO: A dialog will popup but it could get hidden behind the console.
      require( "iuplua" )
ml = iup.multiline
    {
    expand="YES",
    value="Quit this multiline edit app to continue Tutorial!",
    border="YES"
    }
dlg = iup.dialog{ml; title="IupMultiline", size="QUARTERxQUARTER",}
dlg:show()
print("Exit GUI app to continue!")
iup.MainLoop()
      ]==],

      [==[


      print("\nYour Quick Lua Tour is complete!")
      +1 -1Share on Facebook
    • MikeHartMikeHart Guru
      Thanks,

      I am sure that it will be very helpfull for beginners.

      Michael
      http://michaelhartlef.carbonmade.com
      +1 -1Share on Facebook
    • ar2rsawseenar2rsawseen Maintainer
      Ehh, where were you, when I started! :D

      Likes: bravcm, Niicodemus

      http://appcodingeasy.com/Gideros-Mobile
      +1 -1 (+2 / -0 )Share on Facebook
    • PlatypusPlatypus Member
      (Part 1 of 2)
      For Easy Copying and Pasting into Gideros Studio:
       
 
-- QuickLuaTour.lua
--
-- A quick tour of the Lua Scripting Language.
--
-- Created: May 21, 2008,
-- Updated: Sept 4th, 2008 Fix typos, minor changes, better formatting.
-- Author: AGR Wilson
-- Some more updates and fixes by Dirk Feytons.
--
-- To add later? - serialize table, self-executing code, closures, co-routines.
--
 
--[==[
-- First Program.
-- Classic hello program.
print("hello")
]==]
 
 
--[==[
-- Comments.
-- Single line comments in Lua start with double hyphen.
--[[ Multiple line comments start
with double hyphen and two square brackets.
  and end with two square brackets. ]]
 
-- And of course this example produces no
-- output, since it's all comments!
 
]==]
 
--[==[
-- Variables.
-- Variables hold values which have types, variables don't have types.
a=1
b="abc"
c={}
d=print
 
print(type(a))
print(type(b))
print(type(c))
print(type(d))
 
]==]
 
--[==[
-- Variable names.
-- Variable names consist of letters, digits and underscores.
-- They cannot start with a digit.
one_two_3 = 123 -- is valid varable name
 
-- 1_two_3 is not a valid variable name.
 
]==]
 
--[==[
-- More Variable names.
-- The underscore is typically used to start special values
-- like _VERSION in Lua.
print(_VERSION)
 
-- So don't use variables that start with _,
-- but a single underscore _ is often used as a
-- dummy variable.
 
]==]
 
--[==[
-- Case Sensitive.
-- Lua is case sensitive so all variable names & keywords
-- must be in correct case.
ab=1
Ab=2
AB=3
print(ab,Ab,AB)
 
]==]
 
--[==[
-- Keywords.
-- Lua reserved words are: and, break, do, else, elseif,
-- end, false, for, function, if, in, local, nil, not, or,
-- repeat, return, then, true, until, while.
 
-- Keywords cannot be used for variable names,
-- 'and' is a keyword, but AND is not, so it is a legal variable name.
AND=3
print(AND)
 
]==]
 
 
--[==[
-- Strings.
a="single 'quoted' string and double \"quoted\" string inside"
b='single \'quoted\' string and double "quoted" string inside'
c= [[ multiple line
with 'single'
and "double" quoted strings inside.]]
 
print(a)
print(b)
print(c)
 
]==]
 
--[==[
-- Assignments.
-- Multiple assignments are valid.
-- var1,var2=var3,var4
a,b,c,d,e = 1, 2, "three", "four", 5
 
print(a,b,c,d,e)
 
]==]
 
 
--[==[
-- More Assignments.
-- Multiple assignments allows one line to swap two variables.
print(a,b)
a,b=b,a
print(a,b)
 
]==]
 
 
--[==[
-- Numbers.
-- Multiple assignment showing different number formats.
-- Two dots (..) are used to concatenate strings (or a
-- string and a number).
a,b,c,d,e = 1, 1.123, 1E9, -123, .0008
print("a="..a, "b="..b, "c="..c, "d="..d, "e="..e)
 
]==]
 
 
--[==[
-- More Output.
-- More writing output.
print "Hello from Lua!"
print("Hello from Lua!")
 
]==]
 
 
--[==[
-- More Output.
-- io.write writes to stdout but without new line.
io.write("Hello from Lua!")
io.write("Hello from Lua!")
 
-- Use an empty print to write a single new line.
print()
 
]==]
 
--[==[
-- Tables.
-- Simple table creation.
a={} -- {} creates an empty table
b={1,2,3} -- creates a table containing numbers 1,2,3
c={"a","b","c"} -- creates a table containing strings a,b,c
print(a,b,c) -- tables don't print directly, we'll get back to this!!
 
]==]
 
--[==[
-- More Tables.
-- Associate index style.
address={} -- empty address
address.Street="Wyman Street"
address.StreetNumber=360
address.AptNumber="2a"
address.City="Watertown"
address.State="Vermont"
address.Country="USA"
 
print(address.StreetNumber, address["AptNumber"])
 
]==]
 
--[==[
-- if statement.
-- Simple if.
a=1
if a==1 then
    print ("a is one")
end
 
]==]
 
--[==[
-- if else statement.
b="happy"
if b=="sad" then
    print("b is sad")
else
    print("b is not sad")
end
 
]==]
 
--[==[
-- if elseif else statement
c=3
if c==1 then
    print("c is 1")
elseif c==2 then
    print("c is 2")
else
    print("c isn't 1 or 2, c is "..tostring(c))
end
 
]==]
 
--[==[
-- Conditional assignment.
-- value = test and x or y
a=1
b=(a==1) and "one" or "not one"
print(b)
 
-- is equivalent to
a=1
if a==1 then
    b = "one"
else
    b = "not one"
end
print(b)
 
]==]

      Likes: bravcm

      Kate's Catalogue of Travelling Theatre Centres :
      Meet Kate. Grey is her favourite colour. Maths is her favourite subject. Decency is her favourite type of behaviour.
      She definitely does not like jewellery or modelling, but loves aeroplanes and other machines made of aluminium.
      +1 -1 (+1 / -0 )Share on Facebook
    • PlatypusPlatypus Member
      (Part 2 of 2)
      For Easy Copying and Pasting into Gideros Studio:
       
 
--[==[
-- while statement.
a=1
while a~=5 do -- Lua uses ~= to mean not equal
    a=a+1
    io.write(a.." ")
end
 
]==]
 
--[==[
-- repeat until statement.
a=0
repeat
    a=a+1
    print(a)
until a==5
 
]==]
 
--[==[
-- for statement.
-- Numeric iteration form.
-- Count from 1 to 4 by 1.
for a=1,4 do io.write(a) end
 
print()
 
-- Count from 1 to 6 by 3.
for a=1,6,3 do io.write(a) end
 
]==]
 
--[==[
-- More for statement.
-- Sequential iteration form.
for key,value in pairs({1,2,3,4}) do print(key, value) end
 
]==]
 
--[==[
-- Printing tables.
-- Simple way to print tables.
a={1,2,3,4,"five","elephant", "mouse"}
 
for i,v in pairs(a) do print(i,v) end
 
]==]
 
--[==[
-- break statement.
-- break is used to exit a loop.
a=0
while true do
    a=a+1
    if a==10 then
        break
    end
end
 
print(a)
 
]==]
 
--[==[
-- Functions.
-- Define a function without parameters or return value.
function myFirstLuaFunction()
    print("My first lua function was called")
end
 
-- Call myFirstLuaFunction.
myFirstLuaFunction()
 
]==]
 
--[==[
-- More functions.
-- Define a function with a return value.
function mySecondLuaFunction()
    return "string from my second function"
end
 
-- Call function returning a value.
a=mySecondLuaFunction("string")
print(a)
 
]==]
 
--[==[
-- More functions.
-- Define function with multiple parameters and multiple return values.
function myFirstLuaFunctionWithMultipleReturnValues(a,b,c)
    return a,b,c,"My first lua function with multiple return values", 1, true
end
 
a,b,c,d,e,f = myFirstLuaFunctionWithMultipleReturnValues(1,2,"three")
print(a,b,c,d,e,f)
 
]==]
 
--[==[
-- Variable scoping and functions.
-- All variables are global in scope by default.
b="global"
 
-- To make local variables you must put the keyword 'local' in front.
function myfunc()
    local b=" local variable"
    a="global variable"
    print(a,b)
end
 
myfunc()
print(a,b)
 
]==]
 
--[==[
-- Formatted printing.
-- An implementation of printf.
function printf(fmt, ...)
    io.write(string.format(fmt, ...))
end
 
printf("Hello %s from %s on %s\n",
       os.getenv"USER" or "there", _VERSION, os.date())
 
]==]
 
 
--[==[
--[[
 
Standard Libraries
 
Lua has standard built-in libraries for common operations in
math, string, table, input/output & operating system facilities.
 
External Libraries
 
Numerous other libraries have been created: sockets, XML, profiling,
logging, unittests, GUI toolkits, web frameworks, and many more.
 
]]
 
]==]
 
--[==[
-- Standard Libraries - math.
 
-- Math functions:
-- math.abs, math.acos, math.asin, math.atan, math.atan2,
-- math.ceil, math.cos, math.cosh, math.deg, math.exp, math.floor,
-- math.fmod, math.frexp, math.huge, math.ldexp, math.log, math.log10,
-- math.max, math.min, math.modf, math.pi, math.pow, math.rad,
-- math.random, math.randomseed, math.sin, math.sinh, math.sqrt,
-- math.tan, math.tanh
print(math.sqrt(9), math.pi)
 
]==]
 
--[==[
-- Standard Libraries - string.
 
-- String functions:
-- string.byte, string.char, string.dump, string.find, string.format,
-- string.gfind, string.gsub, string.len, string.lower, string.match,
-- string.rep, string.reverse, string.sub, string.upper
print(string.upper("lower"),string.rep("a",5),string.find("abcde", "cd"))
 
]==]
 
--[==[
-- Standard Libraries - table.
 
-- Table functions:
-- table.concat, table.insert, table.maxn, table.remove, table.sort
a={2}
table.insert(a,3);
table.insert(a,4);
table.sort(a,function(v1,v2) return v1 > v2 end)
for i,v in ipairs(a) do print(i,v) end
 
]==]
 
--[==[
-- Standard Libraries - input/output.
 
-- IO functions:
-- io.close , io.flush, io.input, io.lines, io.open, io.output, io.popen,
-- io.read, io.stderr, io.stdin, io.stdout, io.tmpfile, io.type, io.write,
-- file:close, file:flush, file:lines ,file:read,
-- file:seek, file:setvbuf, file:write
       print(io.open("file doesn't exist", "r"))
 
]==]
 
--[==[
-- Standard Libraries - operating system facilities.
 
-- OS functions:
-- os.clock, os.date, os.difftime, os.execute, os.exit, os.getenv,
-- os.remove, os.rename, os.setlocale, os.time, os.tmpname
print(os.date())
 
]==]
 
--[==[
-- External Libraries.
-- Lua has support for external modules using the 'require' function
-- INFO: A dialog will popup but it could get hidden behind the console.
require( "iuplua" )
ml = iup.multiline
    {
    expand="YES",
    value="Quit this multiline edit app to continue Tutorial!",
    border="YES"
    }
dlg = iup.dialog{ml; title="IupMultiline", size="QUARTERxQUARTER",}
dlg:show()
print("Exit GUI app to continue!")
iup.MainLoop()
 
]==]
 
--[==[
 
print("Your Quick Lua Tour is complete!")
 
]==]

      Likes: bravcm

      Kate's Catalogue of Travelling Theatre Centres :
      Meet Kate. Grey is her favourite colour. Maths is her favourite subject. Decency is her favourite type of behaviour.
      She definitely does not like jewellery or modelling, but loves aeroplanes and other machines made of aluminium.
      +1 -1 (+1 / -0 )Share on Facebook
    • fxonefxone Member
      @Platypus is not a better way to put these codes on GitHub site? the thread will be more readable ;)
      http://www.mynameisoriginality.com
      https://play.google.com/store/apps/developer?id=My+name+is+Originality

      +1 -1Share on Facebook
    • PlatypusPlatypus Member
      Sorry.
      Kate's Catalogue of Travelling Theatre Centres :
      Meet Kate. Grey is her favourite colour. Maths is her favourite subject. Decency is her favourite type of behaviour.
      She definitely does not like jewellery or modelling, but loves aeroplanes and other machines made of aluminium.
      +1 -1Share on Facebook
    • ar2rsawseenar2rsawseen Maintainer
      @Platypus oh you don't need to be, sometimes it's useful to dig up old information, that might be valuable ;)
      http://appcodingeasy.com/Gideros-Mobile
      +1 -1Share on Facebook
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