CoutnUnitsInGroup vs FirstOfGroup

08-04-2006, 02:23 AM	#1
The_AwaKening	I noticed in a lot of my older triggers, I was using a blizzard.j function to tell a loop when to exit. exitwhen CountUnitsInGroup(g) == 0 To eliminate that call I'm thinking that this should work exitwhen FirstOfGroup(g) == null Should that be ok, or do I need to set a local unit to the FirstOfGroup first and then check to see if that unit is null. The way I showed above saves ok in WE.

08-04-2006, 02:37 AM	#2
PipeDream	Yes, that is ok. CountUnitsInGroup is rarely the right function for the job.

08-04-2006, 02:38 AM

masda70

Store it in a variable first, if it doesn't return null you will probably need to reference anyways.

You are right to leave countunitsingroup, that function actually uses a ForGroup to count the units in the group...

Given g the group you will loop through:

JASS:

    loop
        set p=FirstOfGroup(g)
        exitwhen (p==null)
        //do stuff with p
        call GroupRemoveUnit(g,p)
    endloop

g will be an empty group at the end and you will probably want to destroy it.

08-04-2006, 09:15 AM	#4
SentryIII	That's interesting to know. I actually use CountUnitsInGroup extensively in my triggers, though I haven't run into any performance issues yet. It's great to know for when I start running into performance problems.

08-06-2006, 12:49 PM	#5
DioD	first of group is better. Cause it return a unit for later use,

08-06-2006, 01:37 PM	#6
Rising_Dusk	Uhm.. CountUnitsInGroup has some aspects that can be useful. Like actually counting units in a group when you need to know that number and can't afford to remove units constantly and need to keep it within the function.

08-06-2006, 02:54 PM	#7
The_AwaKening	Agreed, although looking at the blizzard.j, it almost appears as if it would create a leak because it creates a temporary group to remove the units and count them. I don't see that the tempgroup is ever destroyed. I myself made my own countunitgroups function in the custom script in case I needed it. I never was assuming it was useless, just senseless to check if a group is emtpy by using it.

08-06-2006, 02:57 PM	#8
Rising_Dusk	Well also -- I never use it directly. JASS: set bj_groupCountUnits = 0 call ForGroup(MyGroup, function CountUnitsInGroupEnum) set MyCounter = bj_groupCountUnits That's how I use it.