How to set "trigger device" type Array's element into new array.

[RyuFuru12121]

Hi,

Let me question how to set “trigger device” type Array’s element into new array.
Regarding to the official document,
Array | Epic Developer Community (epicgames.com)

I implemented the following verse code.
However, I confirm on Fortnite, the sentence “if(set “NewArray”[TriggerArrayIndex] = TriggeredCard):” fails to be executed. What is the cause of this problem?

Regards,

using { /Fortnite.com/Devices }
using { /Verse.org/Simulation }
using { /UnrealEngine.com/Temporary/Diagnostics }
using { /UnrealEngine.com/Temporary/SpatialMath }
using { /Verse.org/Random }
using { /Verse.org/Verse }
using { /UnrealEngine.com/Temporary/UI }
using { /Fortnite.com/UI }
using { /Verse.org/Colors }
using { /Verse.org/Simulation/Tags }
using { /Fortnite.com/Playspaces }
using { /Fortnite.com/Characters }
using { /UnrealEngine.com/Temporary/SpatialMath }

prop_teleport := class(creative_device):

    @editable
    TriggerCard : []trigger_device = array{}

    OnBegin<override>()<suspends>:void=
    	# Prepare New Arrays
        var SelectedCards : []trigger_device = array{}
	    var NonSelectedCards : []trigger_device = array{}
	    
	    # Set the original array element into new ones
	    var TriggerArrayIndex : int = 0
	    for(Index -> TriggeredCard : TriggerCard):
	        if(ToString(Index) = CardNo):
	            Print("Test")
	            # This sentence fails to be executed
	            if(set SelectedCards[TriggerArrayIndex] = TriggeredCard):
	                Print("Selected!")
	                set TriggerArrayIndex += 1
	        else:
	            Print("Test2")
	            # This sentence fails to be executed
	            if(set NonSelectedCards[TriggerArrayIndex] = TriggeredCard):
	                Print("Out!")

[adrianjch]

I believe you are just trying to add new elements to the array, right? In that case you should be doing set SelectedCards += array{TriggeredCard}.
The code you are trying to execute currently is searching for the index 0 of an empty array, so it fails because it cannot change its value.

[RyuFuru12121]

Thank you for your reply

I tried to add += with your advise.
However, using += on the code causes Error as the picture shows.

=+ is correct (but with code, the same problem still occur) or is there any problem here?

Regards

[SeedohFN]

You did not write array{TriggeredCard} as mentioned in the previous reply. To add an element to an array you must write the element you want to add inside an array like this for example:
set MyArray += array{MyElement}

[im_a_lama (LAMA)]

Just to complete what @SeedohFN is saying, arrays are immutable in Verse, which means they cannot be modified. So we just replace them instead. When you do :

set MyArray += array{MyElement}

You’re actually creating a new array which is equal to MyArray + array{MyElement} and putting the result inside MyArray again.

Which is also why we have to keep the size of arrays low so that the concatenation doesn’t get too heavy.