HOWTO: Use Spaces in Enumerated Types

• Microsoft Visual Basic Professional and Enterprise Editions, for Windows, version 5.0

SUMMARY

Microsoft Visual Basic version 5.0 introduces the concept of Enumerated Types to the programming language. Enumerations provide a convenient way to work with sets of related constants and to associate constant values with identifiers. The identifier may be defined as either a normal identifier or a more "friendly" identifier that can contain spaces.

NOTE: Other identifiers, such as variable names and procedure names, can not contain spaces.

MORE INFORMATION

Because Enumerated types are defined at the module level, you need to do the following:

1. Start Microsoft Visual Basic version 5.0. Create a new Standard EXE. This will add Form1 to our new project.

2. From the Project menu, click Add Module.

3. Add the following enumerated type to Module1:

         Enum SpecialCharacters1
            TabKey = 12
            EnterKey = 13
            SpaceBar = 32
         End Enum
   
      This allows you to use the constant identifiers TabKey, EnterKey, and
      SpaceBar in place of the values 12, 13, and 32 respectively when you use
      the variable X. However, you are not limited to identifiers that have
      only one word (no spaces) in them. You can allow your enumerated type to
      have much more friendly names by doing the following:
   
   

4. Add the following enumerated type to Module1:

         Enum SpecialCharacters2
            [Tab Key] = 12
            [Enter Key] = 13
            [Space Bar] = 32
         End Enum
   
      By enclosing the identifier in opening and closing brackets ([]), you
      can define a much more readable identifier. You can now use these two
      different enumerated types by defining some procedures:
   
   

5. Add the following code to Module1:

         Sub Main ()
   
         End Sub
   
         Sub Test1 (newVar as SpecialCharacters1)
   
         End Sub
   
         Sub Test2 (newVar as SpecialCharacters2)
   
         End Sub
   
   

6. Now add the statements "Test1" and "Test2" (without quotes) to the Main procedure, which should look like the following:

         Sub Main ()
             Test1
             Test2
         End Sub
   
   

7. Press the spacebar to add the required parameter to the Test1 and Test2 statements. You are provided with the following list of values:

         Test1 EnterKey
               SpaceBar
               TabKey
   
         Test2 Enter Key
               Space Bar
               Tab Key
   
      Note that there are no brackets shown in the list Test2's parameter.
   
   

8. Select the "SpaceBar" value for Test1 and the "Space Bar" value for Test2. Your Main procedure should look like the following:

         Sub Main ()
             Test1 SpaceBar
             Test2 [Space Bar]
         End Sub
   
      Note that the brackets are automatically included for your second
      enumerated type. This is a crucial point. If an enumerated type contains
      friendly identifiers, the brackets must be used to evaluated the
      identifier.
   
   

9. Add a third line to the Main procedure as follows:

         Sub Main ()
             Test1 SpaceBar
             Test2 [Space Bar]
             Test2 Space Bar  'No brackets
         End Sub
   
   

REFERENCES

Microsoft Visual Basic 5.0 Books Online "Using Enumerations to Work with Sets of Constants"

Microsoft Visual Basic Online Help "Enum Statement"

Keywords          : vb5all vb5howto VBKBProgramming vbwin GnrlVb kbprg
Technology        : kbvba
Version           : WINDOWS:5.0
Platform          : WINDOWS
Issue type        : kbhowto