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# isMainWindow

A Boolean value that indicates whether the window is the application’s main window.

```
var isMainWindow: Bool { get }
```

## Discussion

The value of this property is <doc://com.apple.documentation/documentation/Swift/true> when the window is the main window for the application; otherwise, <doc://com.apple.documentation/documentation/Swift/false>.

## See Also

[`isKeyWindow`](/documentation/AppKit/NSWindow/isKeyWindow)

A Boolean value that indicates whether the window is the key window for the application.


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