Local: Difference between revisions

From Multi Theft Auto: Wiki
Jump to navigation Jump to search
No edit summary
 
mNo edit summary
 
(8 intermediate revisions by 6 users not shown)
Line 1: Line 1:
A local varible only exists within the function between "on functionname" and the functions "end" point.
A local variable only exists within the scope it is declared. The scope is the 'level' the variable is visible for the script, containing the value that was assigned to it.


Example:
==Usage==
local playermoney = getPlayerMoney ( source )
You should use local variables anytime it is possible, when you don't need to access them globally. This saves you from having troubles with duplicate variable names. Plus, access to local variables is faster.
 
It is thus also good practice to declare as local any variables that are to exist in any scope within a script file, by declaring it using ''local'' outside any blocks. The main reason to make a variable global in a resource is when it must be accessed by more than one script file in the resource. Since all script files within a resource share the same global environment, it makes sense to use a global variable here.
 
==Examples==
<syntaxhighlight lang="lua">
function showMoney(source)
local playermoney = getPlayerMoney ( source )
outputChatBox(playermoney)
end
</syntaxhighlight>
 
The ''playermoney'' variable only exists within the 'showMoney' function.
 
 
<syntaxhighlight lang="lua">
local showHealth = true
 
outputChatBox("This is your status:", player)
if showHealth == true then
local health = getElementHealth(player)
outputChatBox("Health: "..tostring(health), player)
end
</syntaxhighlight>
 
The ''health'' variable only exists within the ''if''-condition block, that is between the 'then' and the 'end'.
 
==See also==
[http://www.lua.org/pil/4.2.html Programming in Lua: 4.2 Local Variables and Blocks]
 
[[Category:Scripting Concepts]]

Latest revision as of 21:29, 12 May 2009

A local variable only exists within the scope it is declared. The scope is the 'level' the variable is visible for the script, containing the value that was assigned to it.

Usage

You should use local variables anytime it is possible, when you don't need to access them globally. This saves you from having troubles with duplicate variable names. Plus, access to local variables is faster.

It is thus also good practice to declare as local any variables that are to exist in any scope within a script file, by declaring it using local outside any blocks. The main reason to make a variable global in a resource is when it must be accessed by more than one script file in the resource. Since all script files within a resource share the same global environment, it makes sense to use a global variable here.

Examples

function showMoney(source)
	local playermoney = getPlayerMoney ( source )
	outputChatBox(playermoney)
end

The playermoney variable only exists within the 'showMoney' function.


local showHealth = true

outputChatBox("This is your status:", player)
if showHealth == true then
	local health = getElementHealth(player)
	outputChatBox("Health: "..tostring(health), player)
end

The health variable only exists within the if-condition block, that is between the 'then' and the 'end'.

See also

Programming in Lua: 4.2 Local Variables and Blocks