Can someone please explain me this code?

[TopAz]

  
function addNum(...) 
    num = 0 
    for i, b in ipairs{...} do 
        num = num + b 
    end 
    return num 
end 
  

Thanks in advance.

[Castillo]

function addNum ( ... ) 
    local num = 0 
    for i, b in ipairs ( ... ) do -- Loop through the table given.  
        num = num + 1 -- Increase 'num' variable by one. 
    end 
    return num -- Return the 'num' variable. 
end 
  
outputChatBox ( addNum ( { "Hello", "World" } ) ) 

[BinSlayer1]

Useless code.

You could easily use #

such as if the table was called pants you can call #pants and it will return the number of elements

[Kenix]

BinSlayer1,Solidsnake14

*FACEPALM*

Example

function fSize( ... ) 
    return #( ... ) 
end 
  
print( fSize( { [1] = true; [3] = 4 } ) )-- 1 
  

function fSize( ... ) 
    return #( ... ) 
end 
  
print( fSize( { [1] = true; [2] = 2; [3] = 4 } ) ) -- 3 
  
  

It's correct

  
function fTableSize( ... ) 
    local nCount = 0 
    for _ in pairs( ... ) do 
        nCount = nCount + 1 
    end 
    return nCount 
end 
  
print( fTableSize { [1] = 1; [3] = 3 } )-- 2 
  

ipairs looping only numeric indexes in table and in order.

I show upper examples.

Also table.getn, operator # use this method too.

[Castillo]

@Kenix: I only fixed his script, I was going to use "pairs" instead of "ipairs", but I didn't.

[TopAz]

I got another problem.

Why is this

  
local somedata = 
{ 
    ["name"] = "TopAz", 
    ["age"] = "1000", 
    ["profession"] = "Programmer", 
    ["language"] = "CSharp" 
} 
  
for key,value in pairs(somedata) do 
    print(key .. " | " .. value) 
end 
  

Outputting this

  
language | CSharp 
age | 1000 
name | TopAz 
profession | Programmer 
  

Instead of this

  
name | TopAz 
age | 1000 
profession | Programmer 
language | CSharp 
  

[Castillo]

That's because is not an indexed table.

[TopAz]

That's because is not an indexed table.

Do you know how to fix it? ipairs is not working.

[Castillo]

You can do this:

local somedata = 
    { 
        { "name", "TopAz" }, 
        { "age", "1000" }, 
        { "profession", "Programmer" }, 
        { "language", "CSharp" } 
    } 
  
for index, value in ipairs ( somedata ) do 
    print ( value[ 1 ] .. " | " .. value[ 2 ] ) 
end 

[TopAz]

You can do this:

local somedata = 
    { 
        { "name", "TopAz" }, 
        { "age", "1000" }, 
        { "profession", "Programmer" }, 
        { "language", "CSharp" } 
    } 
  
for index, value in ipairs ( somedata ) do 
    print ( value[ 1 ] .. " | " .. value[ 2 ] ) 
end 

Nice idea man. Thanks!

[TopAz]

Last question. How to make a function with optional parameter?

[Castillo]

What do you mean? just fill the arguments you want.

[TopAz]

But it's not working.

  
function lame(great, lol="LOL", hey=2, now="bla") 
    print(great .. " " .. lol .. " " .. hey .. " " .. now) 
end 
  
lame(great, nil, 3, nil) 
  

[Castillo]

That's wrong, correct:

function lame ( great, lol, hey, now ) 
    print ( tostring ( great ) .. " " .. tostring ( lol ) .. " " .. tostring ( hey ) .. " " .. tostring ( now ) ) 
end 
  
lame("great", nil, 3, nil) 

[TopAz]

That's wrong, correct:

function lame ( great, lol, hey, now ) 
    print ( tostring ( great ) .. " " .. tostring ( lol ) .. " " .. tostring ( hey ) .. " " .. tostring ( now ) ) 
end 
  
lame("great", nil, 3, nil) 

So, how to add default value?

[Castillo]

You can use "or".

function lame ( great, lol, hey, now ) 
    print ( great or "None" .." ".. lol or "None" .." ".. hey or "None" .." ".. now or "None" ) 
end 
  
lame("great", nil, 3, nil) 

[TopAz]

You can use "or".

function lame ( great, lol, hey, now ) 
    print ( great or "None" .." ".. lol or "None" .." ".. hey or "None" .." ".. now or "None" ) 
end 
  
lame("great", nil, 3, nil) 

Thanks. Sorry for troubling you so long.

[Castillo]

It's ok .

You're welcome.

[Kenix]

So, how to add default value?

In lua not have defaults arguments ( very bad )

I like it in c++ like languages.

  
function fTest( n ) 
    if type( n ) == 'number' then 
        return n + 1 
    end 
    return 1 
end 
  
print( fTest( 1 ) ) -- 2 
print( fTest( ) ) -- 1 
  

  
function fTestNext( n ) 
    local n = type( n ) == 'number' and n or 1 
    return n + 1 
end 
  
print( fTestNext( 0 ) ) -- 1 
print( fTestNext( ) ) -- 2 
  

Ask questions.

[BinSlayer1]

To implement default values for function parameters just check inside the function (in the header) if the parameter is nil

If it is, initialize it in any way you want (this is a default value). If it's not nil, then your function will use the one supplied

[TopAz]

So, how to add default value?

In lua not have defaults arguments ( very bad )

I like it in c++ like languages.

  
function fTest( n ) 
    if type( n ) == 'number' then 
        return n + 1 
    end 
    return 1 
end 
  
print( fTest( 1 ) ) -- 2 
print( fTest( ) ) -- 1 
  

  
function fTestNext( n ) 
    local n = type( n ) == 'number' and n or 1 
    return n + 1 
end 
  
print( fTestNext( 0 ) ) -- 1 
print( fTestNext( ) ) -- 2 
  

Ask questions.

Can you please explain me this line?

local n = type( n ) == 'number' and n or 1 

[Kenix]

So, how to add default value?

In lua not have defaults arguments ( very bad )

I like it in c++ like languages.

  
function fTest( n ) 
    if type( n ) == 'number' then 
        return n + 1 
    end 
    return 1 
end 
  
print( fTest( 1 ) ) -- 2 
print( fTest( ) ) -- 1 
  

  
function fTestNext( n ) 
    local n = type( n ) == 'number' and n or 1 
    return n + 1 
end 
  
print( fTestNext( 0 ) ) -- 1 
print( fTestNext( ) ) -- 2 
  

Ask questions.

Can you please explain me this line?

local n = type( n ) == 'number' and n or 1 

You define local variable n and you check variable n ( in arguments function ) ( is number ) and you get count this variable.

If variable n not number then local variable n is 1.

[TopAz]

Thanks mate. I have another problem.

How do I evacuate the mysql data table on my local table without needing to assign them manually?

  
local root = getRootElement() 
local connectionHandle; 
  
local pldata =  
{ 
    {"id", "0"}, 
    {"name", "N/A"}, 
    {"age", "0"}, 
    {"profession", "N/A"}, 
    {"language", "N/A"} 
} 
  
addEventHandler("onPlayerJoin", root,  
    function() 
        spawnPlayer(source, 1959.55, -1714.46, 10) 
        fadeCamera(source, true) 
        setCameraTarget(source, source) 
    end 
) 
  
addEventHandler("onResourceStart", root,  
    function() 
        connectionHandle = dbConnect("mysql", "dbname=testgm;host=localhost", "root", "") 
        local query = dbQuery(connectionHandle, "SELECT * FROM `user` WHERE `id` = 1") 
        if query then 
            for key, value in ipairs(dbPoll(query, -1)) do 
                -- how to assign pldata in here automatically? 
            end 
        end 
    end 
) 
  

Edit: Here is the MySQL structure.

Edited April 2, 2012 by Guest

[Kenix]

No problem.

How do I evacuate the mysql data table on my local table without needing to assign them manually?

Not understand.

[TopAz]

No problem.

How do I evacuate the mysql data table on my local table without needing to assign them manually?

Not understand.

I mean how to assign those table with the mysql result table without manually assigning all the values?