Visual Basic for Applications Reference

Deftype Statements

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Used at module level to set the default data type for variables, argument passed to procedures, and the return type for Function and PropertyGet procedures whose names start with the specified characters.


DefBoolletterrange[, letterrange] . . .

DefByteletterrange[, letterrange] . . .

DefIntletterrange[, letterrange] . . .

DefLngletterrange[, letterrange] . . .

DefCurletterrange[, letterrange] . . .

DefSngletterrange[, letterrange] . . .

DefDblletterrange[, letterrange] . . .

DefDecletterrange[, letterrange] . . .

DefDateletterrange[, letterrange] . . .

DefStrletterrange[, letterrange] . . .

DefObjletterrange[, letterrange] . . .

DefVarletterrange[, letterrange] . . .

The required letterrange argument has the following syntax:


The letter1 and letter2 arguments specify the name range for which you can set a default data type. Each argument represents the first letter of the variable, argument, Function procedure, or Property Get procedure name and can be any letter of the alphabet. The case of letters in letterrange isn't significant.


The statement name determines the data type:

Statement Data Type
DefBool Boolean
DefByte Byte
DefInt Integer
DefLng Long
DefCur Currency
DefSng Single
DefDbl Double
DefDec Decimal(not currently supported)
DefDate Date
DefStr String
DefObj Object
DefVar Variant

For example, in the following program fragment, Message is a string variable:

DefStr A-Q
. . .
Message = "Out of stack space."

A Deftype statement affects only the module where it is used. For example, a DefInt statement in one module affects only the default data type of variables, arguments passed to procedures, and the return type for Function and PropertyGet procedures declared in that module; the default data type of variables, arguments, and return types in other modules is unaffected. If not explicitly declared with a Deftype statement, the default data type for all variables, all arguments, all Function procedures, and all PropertyGet procedures is Variant.

When you specify a letter range, it usually defines the data type for variables that begin with letters in the first 128 characters of the character set. However, when you specify the letter range AZ, you set the default to the specified data type for all variables, including variables that begin with international characters from the extended part of the character set (128255).

Once the range AZ has been specified, you can't further redefine any subranges of variables using Deftype statements. Once a range has been specified, if you include a previously defined letter in another Deftype statement, an error occurs. However, you can explicitly specify the data type of any variable, defined or not, using a Dim statement with an Astype clause. For example, you can use the following code at module level to define a variable as a Double even though the default data type is Integer:

DefInt A-Z
Dim TaxRate As Double

Deftype statements don't affect elements of user-defined types because the elements must be explicitly declared.