VB & VBA in a Nutshell: The Language

Dim Statement

Named Arguments

No

Syntax

Dim varname[([subscripts])] [As [New] type] [, 
    varname[([subscripts])] [As [New] type]] . . .

varname

Use: Required

Your chosen name for the variable.

subscripts

Use: Optional

Dimensions of an array variable.

New

Use: Optional

Keyword that creates an instance of an object.

type

Use: Optional

The data type of varname.

Description

Declares and allocates storage space in memory for variables. The Dim statement is used either at the start of a procedure or the start of a module to declare a variable of a particular data type.

Rules at a Glance

• In addition to the Visual Basic data types listed in Chapter 3, type can be an Object, an object type, or a user-defined type. The default data type, when no type is explicitly declared, is Variant.

• Variable-length strings are declared using the syntax:

  Dim variablename As String

  Fixed-length strings, on the other hand, are declared using the syntax:

  Dim variablename As String * length

• You can declare multiple variables in a single Dim statement, but each variable you declare must use a separate As type clause.

• Variables have the following values when they are first initialized with the Dim statement:

  Data Type	Initial Value
  Numeric	0
  Variable-length string	Zero-length string ("")
  Fixed-length string	Padded with zeros
  Variant	Empty
  Object	Nothing

• To use an object variable that has not been declared using the New keyword, the Set statement must assign an object to the variable before it can be used, as ...