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# update()

Updates the window.

```
func update()
```

## Discussion

The `NSWindow` implementation of this method does nothing more than post an [`didUpdateNotification`](/documentation/AppKit/NSWindow/didUpdateNotification) notification to the default notification center. A subclass can override this method to perform specialized operations, but it should send an update message to `super` just before returning. For example, the `NSMenu` class implements this method to disable and enable menu commands.

An `NSWindow` object is automatically sent an `update` message on every pass through the event loop and before it’s displayed onscreen. You can manually cause an `update` message to be sent to all visible `NSWindow` objects through the `NSApplication` [`updateWindows()`](/documentation/AppKit/NSApplication/updateWindows()) method.

## See Also

[`setWindowsNeedUpdate(_:)`](/documentation/AppKit/NSApplication/setWindowsNeedUpdate(_:))

Sets whether the receiver’s windows need updating when the receiver has finished processing the current event.


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