# IParameter<T> interface

Namespace: [Grasshopper2.Parameters](https://developer.rhino3d.com/api/gh2/namespace/grasshopper2.parameters.md) · Assembly: [Grasshopper2](https://developer.rhino3d.com/api/gh2/assembly/grasshopper2.md)

```cs
public interface IParameter<T> : IParameter
```

Generic extension to the IParameter interface for a specific type. Never directly implement this interface, always inherit from [AbstractParameter](https://developer.rhino3d.com/api/gh2/type/grasshopper2.parameters.abstractparameter.md), [Parameter](https://developer.rhino3d.com/api/gh2/type/grasshopper2.parameters.parameter.md), or [Parameter<T>](https://developer.rhino3d.com/api/gh2/type/grasshopper2.parameters.parameter-1.md) instead.

**Type parameters:**

- `T`

**Derived types:** [Parameter<T>](https://developer.rhino3d.com/api/gh2/type/grasshopper2.parameters.parameter-1.md)

## Properties

- [PersistentData](https://developer.rhino3d.com/api/gh2/type/grasshopper2.parameters.iparameter-1/persistentdata.md): Gets or sets the persistent data.
- [Presets](https://developer.rhino3d.com/api/gh2/type/grasshopper2.parameters.iparameter-1/presets.md): Gets or sets the presets.
- [TypeAssistant](https://developer.rhino3d.com/api/gh2/type/grasshopper2.parameters.iparameter-1/typeassistant.md): Gets the type assistant (if any) for the data inside this parameter.

## Inherited Members

- From [IParameter](https://developer.rhino3d.com/api/gh2/type/grasshopper2.parameters.iparameter.md): [Access](https://developer.rhino3d.com/api/gh2/type/grasshopper2.parameters.iparameter/access.md), [AccessVariability](https://developer.rhino3d.com/api/gh2/type/grasshopper2.parameters.iparameter/accessvariability.md), [ColourOverride](https://developer.rhino3d.com/api/gh2/type/grasshopper2.parameters.iparameter/colouroverride.md), [FallbackName](https://developer.rhino3d.com/api/gh2/type/grasshopper2.parameters.iparameter/fallbackname.md), [HardMetaData](https://developer.rhino3d.com/api/gh2/type/grasshopper2.parameters.iparameter/hardmetadata.md), [Inputs](https://developer.rhino3d.com/api/gh2/type/grasshopper2.parameters.iparameter/inputs.md), [Kind](https://developer.rhino3d.com/api/gh2/type/grasshopper2.parameters.iparameter/kind.md), [ModifierIcons](https://developer.rhino3d.com/api/gh2/type/grasshopper2.parameters.iparameter/modifiericons.md), [Modifiers](https://developer.rhino3d.com/api/gh2/type/grasshopper2.parameters.iparameter/modifiers.md), [Outputs](https://developer.rhino3d.com/api/gh2/type/grasshopper2.parameters.iparameter/outputs.md), [PersistentDataWeak](https://developer.rhino3d.com/api/gh2/type/grasshopper2.parameters.iparameter/persistentdataweak.md), [PostProcessInputTrees](https://developer.rhino3d.com/api/gh2/type/grasshopper2.parameters.iparameter/postprocessinputtrees.md), [PresetsWeak](https://developer.rhino3d.com/api/gh2/type/grasshopper2.parameters.iparameter/presetsweak.md), [Requirement](https://developer.rhino3d.com/api/gh2/type/grasshopper2.parameters.iparameter/requirement.md), [SoftMetaData](https://developer.rhino3d.com/api/gh2/type/grasshopper2.parameters.iparameter/softmetadata.md), [TypeAssistantWeak](https://developer.rhino3d.com/api/gh2/type/grasshopper2.parameters.iparameter/typeassistantweak.md), [TypeFlavour](https://developer.rhino3d.com/api/gh2/type/grasshopper2.parameters.iparameter/typeflavour.md), [ClearModifierIcons](https://developer.rhino3d.com/api/gh2/type/grasshopper2.parameters.iparameter/clearmodifiericons.md)
- From [IDocumentObject](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject.md): [Activity](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/activity.md), [Attributes](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/attributes.md), [ChildrenObjects](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/childrenobjects.md), [Connectivity](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/connectivity.md), [CustomValues](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/customvalues.md), [Display](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/display.md), [DisplayCapable](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/displaycapable.md), [DisplayName](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/displayname.md), [DisplayStyle](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/displaystyle.md), [Document](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/document.md), [EntireFamily](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/entirefamily.md), [FoundingObject](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/foundingobject.md), [Icon](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/icon.md), [InstanceId](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/instanceid.md), [Nomen](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/nomen.md), [Obsolete](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/obsolete.md), [ParentObject](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/parentobject.md), [Phase](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/phase.md), [ProgressPercentage](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/progresspercentage.md), [Relevance](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/relevance.md), [Selected](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/selected.md), [Selection](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/selection.md), [SiblingObjects](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/siblingobjects.md), [State](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/state.md), [UserName](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/username.md), [ActivityChanged](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/activitychanged.md), [AutosaveRequested](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/autosaverequested.md), [DisplayChanged](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/displaychanged.md), [DocumentChanged](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/documentchanged.md), [Expired](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/expired.md), [InstanceIdChanged](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/instanceidchanged.md), [LayoutChanged](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/layoutchanged.md), [NameChanged](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/namechanged.md), [RelevanceChanged](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/relevancechanged.md), [SelectedChanged](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/selectedchanged.md), [AddUndoRecord](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/addundorecord.md), [AppendToInputPanel](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/appendtoinputpanel.md), [Compute](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/compute.md), [DisplayBounds](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/displaybounds.md), [DisplayFaces](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/displayfaces.md), [DisplayWires](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/displaywires.md), [Expire](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/expire.md), [GetCreationInfo](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/getcreationinfo.md), [GetModificationInfo](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/getmodificationinfo.md), [ModifyIcon](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/modifyicon.md), [ModifyNameAndInfo](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/modifynameandinfo.md), [OnDisplayChanged](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/ondisplaychanged.md), [OnLayoutChanged](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/onlayoutchanged.md), [OverrideAttributes](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/overrideattributes.md), [RequestAutoSave](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/requestautosave.md), [SetCreationInfo](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/setcreationinfo.md), [SetModificationInfo](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/setmodificationinfo.md), [UpdateDisplay](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.idocumentobject/updatedisplay.md)
- From [IStorable](https://developer.rhino3d.com/api/gh2/type/grasshopperio.istorable.md): [Store](https://developer.rhino3d.com/api/gh2/type/grasshopperio.istorable/store.md)
- From [IReferenceAware](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.ireferenceaware.md): [ExpireReferences](https://developer.rhino3d.com/api/gh2/type/grasshopper2.doc.ireferenceaware/expirereferences.md)