In arcpy's field class
Field—ArcGIS Pro | Documentation
you can check for a field's type
but I suspect you don't want the python api, so if it is for pro's sdk, let me know and I can move your post to the correct part of the Community
What I was looking for is this CheckValue function
but for C# .NET SDK
FieldType Property (Field)—ArcGIS Pro in the Pro SDK section of the help. There are separate help topics for non-python help