Some questions about Lua

[Romester]

I have read the wiki and other guides but I can't seem to understand the concept of Functions and Arguments fully.

hook.Add( "PlayerInitialSpawn", "First_Spawn", function( ply )
    ply:PrintMessage( HUD_PRINTTALK, "Welcome to the server " .. ply:GetName() .. "!" );
end );

In this code, I have some questions.
What is (ply) and why is it written in brackets?
At

( "PlayerInitialSpawn", "First_Spawn", function( ply )

Why are there commas?

I would really appreciate a detailed response about this as I want to understand this and start writing my own code soon.
Thanks :D

[Seris]

Commas are to separate arguments in functions. Hook.add is a function that takes a hook name, an identifier, and a callback function as its arguments, in that order. The ply in parentheses is a variable local to the callback function that is sent to the function when it is called. If you don't understand these concepts I recommend you check out the lua documentation on functions and arguments

[Romester]

Lua documentation?
Where can I find it?

[c👌de_g🎷]

Arguments are provided data elements which are sent in by the engine or a programmer when they call that function. "ply" is just the name that the programmer made for that example; you can name it anything you want like "Player" or "Whatever," so long that you change all uses of "ply" in the code. The commas separate arguments when you call a function: hook.Add takes three arguments: a string for the event (PlayerInitialSpawn), a string for the name of the hook -- which can be anything you want (First_Spawn), and a callback function for when the event occurs.

[editline]20th October 2015[/editline]

[QUOTE=Romester;48944362]Lua documentation?
Where can I find it?[/QUOTE]

[url]http://www.lua.org/docs.html[/url]

If you don't want to get the books, check out the reference manual.

[Seris]

[QUOTE=Romester;48944362]Lua documentation?
Where can I find it?[/QUOTE]
Here is the lua reference manual
[URL="http://www.lua.org/manual/5.1/manual.html"]http://www.lua.org/manual/5.1/manual.html[/URL]

[DamienTehDemo]

[QUOTE=Romester;48944266]
In this code, I have some questions.
What is (ply) and why is it written in brackets?
At

( "PlayerInitialSpawn", "First_Spawn", function( ply )

Why are there commas?[/QUOTE]

So basically the ply variable is the player thats spawning first time. What your looking at is a hook. It is called whenever said action happens. So the idea is, if oyu have a player spawning the first time, you have a way to detect it, and when it detects it, it calls the function you defined, giving the ply a actaul value, the player that joined. Sorry if i didnt help i tried my best XD

[Romester]

Thanks everyone for helping me out!