[Visual Basic 6.0]
The following code reports the name of the spatial reference of a layer:
Sub ReportSpatRef()
  Dim pMxDoc as IMxDocument
  Dim pMap as IMap
  Dim pGeoDataset as IGeoDataset
  Dim pSpatRef as ISpatialReference
  
  Set pMxDoc = Application.Document
  Set pMap = pMxDoc.FocusMap
  Set pGeoDataset = pMap.Layer(0)
  Set pSpatRef = pGeoDataset.SpatialReference
  MsgBox pSpatRef.Name
End Sub

[C#]
    //IGeoDataset SpatialReference Example
    public void IGeoDataset_SpatialReference_Example(IFeatureClass featureClass)
    {
        //This function reports the name of spatial reference for a feature class
        IGeoDataset geoDataset = (IGeoDataset)featureClass;
        ESRI.ArcGIS.Geometry.ISpatialReference spatialReference = geoDataset.SpatialReference;
        Console.WriteLine("The featureClass {0} has a spatial reference named {1}", featureClass.AliasName, spatialReference.Name);
    }

[Visual Basic .NET, C++]
No example is available for Visual Basic .NET or C++. To view a Visual Basic 6.0 or C# example, click the Language Filter button in the upper-left corner of the page.