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# windowNumber

The window number of the window’s window device.

```
var windowNumber: Int { get }
```

## Discussion

Each window device in an application is given a unique window number—note that this isn’t the same as the global window number assigned by the window server. This number can be used to identify the window device with the [`order(_:relativeTo:)`](/documentation/AppKit/NSWindow/order(_:relativeTo:)) method and in the AppKit function [`NSWindowList`](/documentation/AppKit/NSWindowList).

If the window doesn’t have a window device, the value of this property is equal to or less than `0`.

## See Also

[`oneShot`](/documentation/AppKit/NSWindow/isOneShot)

A Boolean value that indicates whether the window device the window manages is freed when it’s removed from the screen list.

[`-  initWithContentRect:styleMask:backing:defer:`](/documentation/AppKit/NSWindow/init(contentRect:styleMask:backing:defer:))

Initializes the window with the specified values.


---

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