Arrays, maps and sets

Change individual entries in array, map and set properties without rewriting the whole list.

What it’s for

Unreal objects keep a lot of their state in lists: an array of waypoints, a map of tags to values, a set of allowed classes. Ask your assistant to change one entry in one of these lists on any object, and it leaves the rest alone.

Use it to add a value to the end of a list, change the item at a position, add or remove a key in a map, or add or drop a member of a set. Your assistant can also check what is already there first, such as the keys in a map or whether a value is already in a set.

To replace a whole value at once, see Object properties. This area is for small changes to one entry.

Things you can ask

Add an item to a list

One entry goes on the end of the list, and the rest stays as it was.

You: Add "/Game/Tracks/Canyon" to the AllowedTracks list on the game mode.

Added /Game/Tracks/Canyon to the end of AllowedTracks on BP_RaceMode.

Set a value in a map

Your assistant changes only the one key you name.

You: On the config object, set the "maxPlayers" score limit to 8.

ScoreLimits on DA_MatchConfig had no maxPlayers entry, so I added it with a value of 8.

Add a member to a set

One value joins the set, and existing members stay as they are.

You: Add the "Fog" tag to the enabled weather effects set.

Added Fog to EnabledEffects on BP_Weather.