# holdingPriorityForSubview(at:) Returns the priority of the subview’s width or height when resizing. ``` func holdingPriorityForSubview(at subviewIndex: Int) -> NSLayoutConstraint.Priority ``` ## Parameters `subviewIndex` The index of the subview. ## Return Value The layout priority of the subview at the index. ## Discussion The priority is the manner that the split view subviews use to maintain their width (for a vertical split view) or height (for a horizontal split view). During a split view resize, subviews with higher priorities maintain their sizes before subviews with lower priorities. The subview with the lowest priority is the first to gain additional thickness if the split view grows or shrinks. --- 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)