---
title: NSLayoutConstraint.Attribute.notAnAttribute
framework: uikit
role: symbol
role_heading: Case
path: uikit/nslayoutconstraint/attribute/notanattribute
---

# NSLayoutConstraint.Attribute.notAnAttribute

A placeholder value for indicating that the constraint’s second item and second attribute aren’t used in any calculations.

## Declaration

```swift
case notAnAttribute
```

## Discussion

Discussion Use this value when creating a constraint that assigns a constant to an attribute. For example, item1.height >= 40. If a constraint only has one item, set the second item to nil, and set the second attribute to NSLayoutConstraint.Attribute.notAnAttribute.

## See Also

### Constants

- [NSLayoutConstraint.Attribute.left](uikit/nslayoutconstraint/attribute/left.md)
- [NSLayoutConstraint.Attribute.right](uikit/nslayoutconstraint/attribute/right.md)
- [NSLayoutConstraint.Attribute.top](uikit/nslayoutconstraint/attribute/top.md)
- [NSLayoutConstraint.Attribute.bottom](uikit/nslayoutconstraint/attribute/bottom.md)
- [NSLayoutConstraint.Attribute.leading](uikit/nslayoutconstraint/attribute/leading.md)
- [NSLayoutConstraint.Attribute.trailing](uikit/nslayoutconstraint/attribute/trailing.md)
- [NSLayoutConstraint.Attribute.width](uikit/nslayoutconstraint/attribute/width.md)
- [NSLayoutConstraint.Attribute.height](uikit/nslayoutconstraint/attribute/height.md)
- [NSLayoutConstraint.Attribute.centerX](uikit/nslayoutconstraint/attribute/centerx.md)
- [NSLayoutConstraint.Attribute.centerY](uikit/nslayoutconstraint/attribute/centery.md)
- [NSLayoutConstraint.Attribute.lastBaseline](uikit/nslayoutconstraint/attribute/lastbaseline.md)
- [NSLayoutConstraint.Attribute.firstBaseline](uikit/nslayoutconstraint/attribute/firstbaseline.md)
- [NSLayoutConstraint.Attribute.leftMargin](uikit/nslayoutconstraint/attribute/leftmargin.md)
- [NSLayoutConstraint.Attribute.rightMargin](uikit/nslayoutconstraint/attribute/rightmargin.md)
- [NSLayoutConstraint.Attribute.topMargin](uikit/nslayoutconstraint/attribute/topmargin.md)