The user-input methods provide a certain amount of inherent error trapping in that they require the user to enter a certain type of data.
If the user tries to enter some other data, AutoCAD rejects the input and reprompts the user. Using the InitializeUserInput method with the user input functions provides additional control of the user input but can also introduce additional conditions that must be verified through error trapping. For an example of error trapping that is required with certain types of user-input.