# init(_:children:displayStyle:ancestorRepresentation:) Creates a mirror representing the given subject using a dictionary literal for the structure. ``` init(_ subject: Subject, children: KeyValuePairs, displayStyle: Mirror.DisplayStyle? = nil, ancestorRepresentation: Mirror.AncestorRepresentation = .generated) ``` ## Parameters `subject` The instance to represent in the new mirror. `children` A dictionary literal to use as the structure for the mirror. The `children` collection of the resulting mirror may be upgraded to a random access collection later. See the `children` property for details. `displayStyle` The preferred display style for the mirror when presented in the debugger or in a playground. The default is `nil`. `ancestorRepresentation` The means of generating the subject’s ancestor representation. `ancestorRepresentation` is ignored if `subject` is not a class instance. The default is `.generated`. ## Discussion You use this initializer from within your type’s `customMirror` implementation to create a customized mirror. Pass a dictionary literal with string keys as `children`. Although an *actual* dictionary is arbitrarily-ordered, when you create a mirror with a dictionary literal, the ordering of the mirror’s `children` will exactly match that of the literal you pass. If `subject` is a class instance, `ancestorRepresentation` determines whether ancestor classes will be represented and whether their `customMirror` implementations will be used. By default, the `customMirror` implementation of any ancestors is ignored. To prevent bypassing customized ancestors, pass `.customized({ super.customMirror })` as the `ancestorRepresentation` parameter when implementing your type’s `customMirror` property. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)