rules

.cursor/rules/roblox/luau/nil.md

@@ -0,0 +1,49 @@
+---
+title: Nil
+description: Data type representing non-existence or nothingness.
+---
+
+In Luau, `nil` represents non-existence or nothingness. It's different from any other value or data type. You can use it to destroy a variable or remove a value in a table. It's the only value other than `false` which doesn't evaluate to [`true`](./booleans.md).
+
+Luau has a **garbage collector** that removes data that is no longer accessible by any script. For best performance, redefine large variables as `nil` in long-running scripts when you don't need them anymore so the garbage collector removes them.
+
+```lua
+local variableToDelete = 5
+print(variableToDelete) -- 5
+variableToDelete = nil
+print(variableToDelete) -- nil
+
+local dictionaryTable = {
+	Monday = 1,
+	Tuesday = 2,
+	Wednesday = 3
+}
+-- Output value of 'Tuesday' key
+print(dictionaryTable.Tuesday) -- 2
+-- Clear 'Tuesday' key
+dictionaryTable.Tuesday = nil
+-- Output value of key again
+print(dictionaryTable.Tuesday) -- nil
+```
+
+You can use `nil` to clear some properties of objects. For example, you can set the `Parent` of an object to `nil` to effectively remove the object from the experience. To return the object to the experience after you remove it, reassign the `Parent`. The following example demonstrates how to use `nil` to remove a `Class.Part`:
+
+```lua
+local Workspace = game:GetService("Workspace")
+
+-- Create a new brick
+local part = Instance.new("Part")
+-- Parent new part to the workspace, making it viewable
+part.Parent = Workspace
+task.wait(1)
+-- Remove the part from view but not from memory
+part.Parent = nil
+task.wait(1)
+-- Part still exists because it's referenced by the variable "part", so it can be returned to view
+part.Parent = Workspace
+task.wait(1)
+-- Remove the part from view again
+part.Parent = nil
+-- Clear part reference so it gets picked up by the garbage collector
+part = nil
+```