<!--
{
  "availability" : [
    "iOS: 3.0.0 -",
    "iPadOS: 3.0.0 -",
    "macCatalyst: 13.1.0 -",
    "macOS: 10.5.0 -",
    "tvOS: -",
    "visionOS: 1.0.0 -",
    "watchOS: 2.0.0 -"
  ],
  "documentType" : "symbol",
  "framework" : "CoreData",
  "identifier" : "/documentation/CoreData/NSPropertyMapping/valueExpression",
  "metadataVersion" : "0.1.0",
  "role" : "Instance Property",
  "symbol" : {
    "kind" : "Instance Property",
    "modules" : [
      "Core Data"
    ],
    "preciseIdentifier" : "c:objc(cs)NSPropertyMapping(py)valueExpression"
  },
  "title" : "valueExpression"
}
-->

# valueExpression

The value expression for the property mapping.

```
var valueExpression: NSExpression? { get set }
```

## Discussion

The expression is used to create the value for the destination property.

---

Copyright &copy; 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)