Question about temp variable

[Kurnelia'zooz]

I have just used World Editor recently. When I look at the forum, I always see that people prefer using temp variable than not. Can I ask the differents between two trigger down here? Which trigger is better?

• Untitled Trigger 001 Copy
  • Events
    • Unit - A unit Starts the effect of an ability
  • Conditions
    • ((Triggering unit) is A Hero) Equal to True
  • Actions
    • If (All Conditions are True) then do (Then Actions) else do (Else Actions)
      • If - Conditions
        • (Ability being cast) Equal to War Stomp
      • Then - Actions
        • Set temp_point = (Position of (Triggering unit))
        • Set temp_group = (Units within 350.00 of temp_point matching (((Owner of (Matching unit)) is an enemy of (Owner of (Triggering unit))) Equal to True))
        • Custom script: call RemoveLocation(udg_temp_point)
        • Unit Group - Pick every unit in temp_group and do (Actions)
          • Loop - Actions
            • Unit - Cause (Triggering unit) to damage (Picked unit), dealing (Real((Strength of (Triggering unit) (Include bonuses)))) damage of attack type Spells and damage type Normal
        • Custom script: call RemoveGroup(udg_temp_group)
      • Else - Actions
        • Do nothing

• Untitled Trigger 001
  • Events
    • Unit - A unit Starts the effect of an ability
  • Conditions
    • ((Triggering unit) is A Hero) Equal to True
  • Actions
    • If (All Conditions are True) then do (Then Actions) else do (Else Actions)
      • If - Conditions
        • (Ability being cast) Equal to War Stomp
      • Then - Actions
        • Unit Group - Pick every unit in (Units within 350.00 of (Position of (Triggering unit)) matching (((Owner of (Matching unit)) is an enemy of (Owner of (Triggering unit))) Equal to True)) and do (Actions)
          • Loop - Actions
            • Unit - Cause (Triggering unit) to damage (Picked unit), dealing (Real((Strength of (Triggering unit) (Include bonuses)))) damage of attack type Spells and damage type Normal
        • Unit Group - Remove all units from (Last created unit group)
      • Else - Actions
        • Do nothing

 

[Marcos_M]

The answer is (at least the important one) "Memory Leaks"

This tutorial explain it better
Memory Leaks

Also, "Last created unit group" doesn't work like that, whenever you use the action "Create N units", all those units are stored in "Last created unit group"

 

[Rahko]

People usually prefer temp variables, so that they don't have to potentially make hundreds of variables for each trigger. Instead, if a variable is used just once for one purpose, it can be recycled. Imagine for example if your War Stomp there made a random damage: you could set TempReal = (random real between X and Y); there's no point to save that number after you've dealt the damage, so you can re-use that same TempReal variable in other triggers.

Also, a little side note: you don't need the "do nothing" action.

 

[Pyrogasm]

Another benefit is reducing the number of operations in particularly long code or code that runs frequently. If you use “Player number of (Owner of (Triggering Unit))” 9 times in a trigger then you should store that in a temp variable so it only has to be computed once every time the trigger runs instead of 9 times.

 

[Kurnelia'zooz]

Ok, i got it. Thank you.