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Unit 4: VB Programming Fundamentals

4. Boolean
Boolean data types hold either a true or false value. These are not stored as numeric values and
cannot be used as such. Values are internally stored as -1 (True) and 0 (False) and any non-zero
value is considered as true.

5. Variant
Stores any type of data and is the default Visual Basic data type. In Visual Basic if we declare
a variable without any data type by default the data type is assigned as default.

4.1.1 Visual Basic Data Types

Data Type Suffix

Boolean None
Integer %
Long (Integer) &
Single (Floating) !
Double (Floating) #
Currency @
Date None
Object None
String $
Variant None

4.1.2 Verifying Data Types

You can change a variables type with ReDim in Visual Basic, assign objects to variables using
Set, and even convert standard variables into arrays. For these and other reasons, Visual Basic
has a number of data verification functions, which appear in next page and you can use these
functions to interrogate objects and determine their types.
Verification
function. Dose This
Function
Is Array () Returns True if passed an array
Is Date() Returns True if passed a data
Is Empry() Returns True if passed variable is uninitialized
Is Error() Returns True if passed an error value
Is Missing() Returns True if value was not passed for specified parameter in procedure call
Is Null() Returns True if passed NULL
Is Numeric() Returns True if passed a numeric value
Is Object() Returns True if passed an object

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