INF: Function to Return a Variant's Data Type Name

Article ID: Q120496
Creation Date: 13-SEP-1994
Revision Date: 19-SEP-1996

The information in this article applies to:

Microsoft Access versions 1.0, 1.1, 2.0

SUMMARY

Moderate: Requires basic macro, coding, and interoperability skills.

The VarType() function returns a number (from 0 to 8) indicating the data type used to store a Variant in Access Basic. This article describes a sample user-defined Access Basic function that you can use to return a text description of the data type, instead of just a number.

This article assumes that you are familiar with Access Basic and with creating Microsoft Access applications using the programming tools provided with Microsoft Access. For more information on Access Basic, please refer to the "Introduction to Programming" manual in Microsoft Access version 1.x, or the "Building Applications" manual in version 2.0.

MORE INFORMATION

The following table lists the numbers returned by the VarType() function and their data type descriptions:

   Number Returned   Data Type Description
   ---------------------------------------
         0                 Empty
         1                 Null
         2                 Integer
         3                 Long
         4                 Single
         5                 Double
         6                 Currency
         7                 Date
         8                 String

The following steps demonstrate how to set up the sample function DataTypeName():

Create a new module and enter the following lines in the Declarations section of the module:
```
      Option Compare Database
      Option Explicit
```

Create the following function in the module.

NOTE: In the following sample code, an underscore (_) at the end of a line is used as a line-continuation character. Remove the underscore from the end of the line when re-creating this code in Access Basic.

      '================================================================
      ' This function returns a text description of the number returned
      ' by the VarType() function.
      '================================================================
      Function DataTypeName (MyValue)
         On Error goto bye
         DataTypeName = Choose(VarType(MyValue) + 1, "Empty", "Null", _
         "Integer","Long", "Single", "Double", "Currency", "Date", _
         "String")
         bye:
      End Function

From the View menu, choose Immediate Window. Type the following line in the Immediate window, and then press ENTER:
```
      ?DataTypeName((Date()))
```
The function returns "Date," indicating the Date/Time data type.
Type the following line in the Immediate window, and then press ENTER:
```
      ?DataTypeName(Str$(1234.56))
```
Note that the function returns "String," indicating a String data type.
Type the following line in the Immediate window and then press ENTER:
```
      ?DataTypeName(Val("1234.56"))
```
Note that the function returns "Double," indicating a Double data type.

REFERENCES

Microsoft Access "Language Reference," version 1.1, pages 65 and 492-495

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