Changed
The Changed event fires right after most properties change on objects. It is possible to find the present value of a changed property by using object[property]. To get the value of a property before it changes, you must have stored the value of the property before it changed.
If you are only interested in listening to the change of a specific property, consider using the GetPropertyChangedSignal method instead to get an event that only fires when a given property changes.
This event does not fire for physics-related changes, like when the CFrame, Velocity, RotVelocity, Position, Orientation and CFrame properties of a BasePart change due to gravity. To detect changes in these properties, consider using a physics-based event like RunService.Stepped or BasePart.Touched. A while-true-do loop can also work.
For “-Value” objects, this event behaves differently: it only fires when the Value property changes. See individual pages for IntValue, StringValue, etc for more information. To detect other changes in these objects, you must use GetPropertyChangedSignal instead.
Parameters
| Name | Type | Default | Description |
|---|---|---|---|
|
|
The name of the property that changed. |
Code Samples
Changed Event
This sample demonstrates the subtleties of the Changed event on normal objects and “-Value” objects.
-- Demonstrate the Changed event by creating a Part
local part = Instance.new("Part")
part.Changed:Connect(print)
-- This fires Changed with "Transparency"
part.Transparency = .5
-- Similarly, this fires Changed with "Number"
part.Name = "SomePart"
-- Since changing BrickColor will also change other
-- properties at the same time, this line fires Changed
-- with "BrickColor", "Color3" and "Color3uint16".
part.BrickColor = BrickColor.Red()
-- A NumberValue holds a double-precision floating-point number
local vNumber = Instance.new("NumberValue")
vNumber.Changed:Connect(print)
-- This fires Changed with 123.456 (not "Value")
vNumber.Value = 123.456
-- This does not fire Changed
vNumber.Name = "SomeNumber"
-- A StringValue stores one string
local vString = Instance.new("StringValue")
vString.Changed:Connect(print)
-- This fires Changed with "Hello" (not "Value")
vString.Value = "Hello"
Change Detector
This code sample demonstrates the Changed event firing within a parent object.
local object = script.Parent
local function onChanged(property)
-- Get the current value of the property
local value = object[property]
-- Print a message saying what changed
print(object:GetFullName() .. "." .. property .. " (" .. typeof(value) .. ") changed to " .. tostring(value))
end
object.Changed:Connect(onChanged)
-- Trigger a simple change in the object (add an underscore to the name)
object.Name = "_" .. object.Name