Creating a feature class

You will continue to work at the geodatabase structure by creating four feature classes: Buildings (polygon features), Watercourse (polygon features), WatercourseL (polyline features), and LandUse (polygon features).

Follow these steps to create feature classes using the ArcCatalog context menu:

For every feature class, you defined different attribute fields. Because the WatercourseL feature class has the same attribute fields as Watercourse, you imported the field definitions from Watercourse at step 7. For all attribute fields, you have selected Yes for Allow NULL values. When you add a new feature in ArcMap, the attribute field will have a NULL value or an empty value that will be ignored by the functions in ArcMap. To enforce data integrity, you can specify that a field cannot contain empty or null values by setting Allow NULL values to No. This condition can be validated in the ArcMap edit session using the Validate Features option from Editor in Editor toolbar. You have another option to enforce field values by setting the Default Value property. A default value is automatically assigned to an attribute field when a new feature is being created in the ArcMap edit session.

Regarding spatial reference of the feature class, if you want to move WatercourseL in the LandUse feature dataset, you simply select the feature class and drag and drop it into the LandUse feature dataset. You will succeed because both feature datasets have the same spatial reference. If you drag and drop the WatercourseL feature class into the root of the geodatabase, you will have a standalone feature class.