# IGH_ExpressionParameter interface

Namespace: [Grasshopper.Kernel.Parameters](https://developer.rhino3d.com/api/gh1/namespace/grasshopper.kernel.parameters.md) · Assembly: [Grasshopper](https://developer.rhino3d.com/api/gh1/assembly/grasshopper.md)

```cs
public interface IGH_ExpressionParameter
```

Utility interface used for undo grouping.

**Derived types:** [GH_ExpressionParam<T>](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.parameters.gh-expressionparam-1.md), [Param_Point](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.parameters.param-point.md)

## Properties

- [Expression](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.parameters.igh-expressionparameter/expression.md)