PRB: Correct Usage of "&" and "AND" in Visual Basic (165920)
The information in this article applies to:
- Microsoft Visual Basic Learning Edition for Windows 5.0
- Microsoft Visual Basic Learning Edition for Windows 6.0
- Microsoft Visual Basic Professional Edition for Windows 5.0
- Microsoft Visual Basic Professional Edition for Windows 6.0
- Microsoft Visual Basic Enterprise Edition for Windows 5.0
- Microsoft Visual Basic Enterprise Edition for Windows 6.0
- Microsoft Visual Basic Standard Edition, 32-bit, for Windows 4.0
- Microsoft Visual Basic Professional Edition, 16-bit, for Windows 4.0
- Microsoft Visual Basic Professional Edition, 32-bit, for Windows 4.0
- Microsoft Visual Basic Enterprise Edition, 16-bit, for Windows 4.0
- Microsoft Visual Basic Enterprise Edition, 32-bit, for Windows 4.0
This article was previously published under Q165920 SYMPTOMS
This code works in Visual Basic 3.0:
If Form1.Text1.Text = "" & Form1.Text2.Text = "" Then...
but fails in Visual Basic 4.0 and later with a "type mismatch" error.
The correct syntax for this statement is:
If Form1.Text1.Text = "" And Form1.Text2.Text = "" Then...
Confusing the concatenation operator "&" with the logical operator "AND"
will result in "type mismatch errors."
CAUSE
This is a result of the data type of (Boolean) being added to
Visual Basic 4.0 and later.
RESOLUTION
When performing logical comparisons between operands, be sure to use the
logical operators (AND, OR) as opposed to the concatenation operator "&" in
Visual Basic 4.0.
STATUS
This is by design.
MORE INFORMATION
In Visual Basic 3.0, a logical comparison between operands would result in
either a 1 or a 0 being returned. With Visual Basic 4.0 and later, a
logical data type has been added so that a logical comparison between two
operands will result in either a "TRUE" or "FALSE" value being returned.
Attempting to use the concatenation operator "&" can not be performed in
Visual Basic 4.0 and later on these logical data types. Therefore, an error
is raised.
| Modification Type: | Minor | Last Reviewed: | 7/14/2004 |
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| Keywords: | kbprb KB165920 |
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