Hollywood forums

Posted: **Wed Dec 21, 2022 11:39 am**

I accidentally did some bad code today by not having sent necessary information to the Function, but used those variables from outside the function, and it worked.

here an example:

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Function myfunc()
	DebugPrint(n)
EndFunction

For n = 1 To 3
myfunc()
Next

Normally I would send that n as one of the arguments to "myfunc", but this time I didnt.

As I was wondering about this, this could actually be somewhat handy way to make code cleaner in some cases, like:

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for n = 1 to 100
DrawEnemy()
next

instead of:

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for n=1 to 100
DrawEnemy(Enemy[n].x, Enemy[n].y, Enemy[n].Weapon, Enemy[n].status,Enemy[n].whatevermore)
next

But is this a safe way to do this otherwise, except that n cant be Local, which in itself can cause problems?

Posted: **Thu Dec 22, 2022 2:43 am**

The object oriented approach would be to replace DrawEnemy() with a draw() method contained in the enemy table structure. Then you could draw them using an iterator and making the [n] lookups into uses of the self variable in the method.

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Enemies={}
/* global acceleration */
global dx=3
global dy=4

Function createEnemy()
   local enemy={}
   enemy.x=0
   enemy.y=0
   ...
   return(enemy)
EndFunction

Function Enemy:draw()
   ...
EndFunction

Function Enemy:update()
   self.x=self.x+dx
   self.y=self.y+dy
   ...
   self:draw()
EndFunction

For k,v in IPairs(Enemies) Do v:update()

Or if you have a bunch of code written already, pass the table variable Enemy[n] in as a parameter and just do table lookups based on that.

Posted: **Thu Dec 22, 2022 2:28 pm**

@SamuraiCrow

True, but wasn't looking at solution to that specific example, just giving generic example about what it could solve, although, indeed, it was a bad example since there is more obvious solution available, the one that you suggested.

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is it safe to use variables not sent to func

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