Array: build dynamic list, iterate, find and remove items

ADD: Array Add (Target Array=MyArray, New Item=newElement). READ: Array Get (Target Array=MyArray, Index=i) → use 'Item' output. FIND: Array Contains (returns bool) or Array Find (returns index, -1 if not found). REMOVE by index: Array Remove (Target Array=MyArray, Index=i). REMOVE by value: Array Remove Item (Target Array=MyArray, Item=value). ITERATE: ForEachLoop(Array=MyArray) → 'Array Element' output is the current item. LENGTH: Array Length (returns int). Key: Array nodes operate on the array BY REFERENCE — always connect the array variable directly.

Array

An ordered list of values of one type. Add/Remove/Find/Get by index. Pair with ForEachLoop for iteration.

Performance optimization checklist for Blueprints

1. TICK MANAGEMENT: - Disable tick on static actors (SetActorTickEnabled=false). - Use SetActorTickInterval(0.1-0.5) for AI, non-critical systems. - Prefer event-driven over tick polling where possible. 2. AVOID EVERY-TICK EXPENSIVE CALLS: - GetAllActorsOfClass: cache in BeginPlay, refresh only when needed. - CastTo: cache result in variable after first cast. - GetComponentByClass: call once and store reference. 3. VISIBILITY: - SetActorHiddenInGame + SetActorTickEnabled=false for off-screen actors. - Use LOD (Level of Detail) on meshes. 4. SPAWNING: - Use object pooling for frequently spawned/destroyed actors (bullets, effects). 5. EVENTS OVER POLLING: - Use overlap events instead of periodic distance checks. - Use delegates/dispatchers instead of checking conditions each frame.

GetAllActorsOfClass — get an array of all actors of a specific class

Expensive — avoid calling every Tick. Cache results or use delegates instead.

string

string

GetAllActorsOfClass — find all actors of a specific class in the level

UGameplayStatics::GetAllActorsOfClass. Expensive — cache results, don't call every tick.

Not_PreBool — logical NOT

Pickup and collectible system with overlap trigger

Pattern: Pickup actor with SphereCollision(overlap), StaticMesh visual. OnComponentBeginOverlap → CastTo PlayerCharacter → Success: call AddScore/AddItem interface on player → PlaySoundAtLocation → SpawnEmitterAtLocation → DestroyActor(self). Set collision to OverlapOnlyPawn for performance.

Inventory system with array of structs for items

Pattern: Struct S_InventoryItem(ItemName:String, Quantity:int, Icon:Texture2D, bStackable:bool). Variable Inventory(Array<S_InventoryItem>). AddItem: ForEachLoop(Inventory) → Branch(Element.ItemName == NewItem.Name AND bStackable) → True: SET Element.Quantity += Amount. If not found: Array_Add(NewItem). RemoveItem: Find index → Branch(Quantity > 1) → True: decrement. False: Array_Remove.

Inventory: add/remove items with array of structs

Create struct FInventoryItem: {ItemName (Name), ItemCount (int), ItemData (object ref)}. Variable: Inventory (Array<FInventoryItem>). AddItem: ForEachLoop(Inventory) → CastTo/Break FInventoryItem → Branch(ItemName==NewItem.Name) → True: Get → Modify Count → Array Set (replace at index) → return. If not found: Make FInventoryItem → Array Add. RemoveItem: Find by name → Branch(Count>1) → True: decrement → Set at index. Else: Array Remove at index. Key: Arrays of structs require 'Array Set' with index to modify in place — getting and modifying a copy does NOT update the array.