---
title: expression
framework: coredata
role: symbol
role_heading: Instance Property
path: coredata/nsexpressiondescription/expression
---

# expression

The expression to evaluate.

## Declaration

```swift
var expression: NSExpression? { get set }
```

## See Also

### Configuring the Expression Description

- [resultType](coredata/nsexpressiondescription/resulttype.md)
- [expressionResultType](coredata/nsexpressiondescription/expressionresulttype.md)