# IOneAndOnlyOneSelection Interface

Namespace: [Qlik.Engine](https://help.qlik.com/en-US/sense-developer/November2024/Subsystems/NetSDKAPIref/Content/Qlik.Engine.htm)  
Assembly: Qlik.Engine.dll

## Syntax

```
[ValueClass]
public interface IOneAndOnlyOneSelection
```

## Properties

| Name | Description |
| --- | --- |
| [Cardinality](https://help.qlik.com/en-US/sense-developer/November2024/Subsystems/NetSDKAPIref/Content/Qlik.Engine.IOneAndOnlyOneSelection.Cardinality.htm#Qlik_Engine_IOneAndOnlyOneSelection_Cardinality) | JSON property name: qCardinality |
| [SelectedIndex](https://help.qlik.com/en-US/sense-developer/November2024/Subsystems/NetSDKAPIref/Content/Qlik.Engine.IOneAndOnlyOneSelection.SelectedIndex.htm#Qlik_Engine_IOneAndOnlyOneSelection_SelectedIndex) | JSON property name: qSelectedIndex |
| [Value](https://help.qlik.com/en-US/sense-developer/November2024/Subsystems/NetSDKAPIref/Content/Qlik.Engine.IOneAndOnlyOneSelection.Value.htm#Qlik_Engine_IOneAndOnlyOneSelection_Value) | JSON property name: qValue |