---
title: "subscript(dynamicMember:)"
framework: swiftui
role: symbol
role_heading: Instance Subscript
path: "swiftui/attributedtextformatting/attributecontainerproxy/subscript(dynamicmember:)"
---

# subscript(dynamicMember:)

Access the value of the attribute to constrain.

## Declaration

```swift
subscript(dynamicMember keyPath: KeyPath<AttributeDynamicLookup, Attribute>) -> Attribute.Value? { get set }
```

## Overview

Overview For details on how attribute value constraining works, refer to constrain(_:).