VBA - Variables

Variable is a named memory location used to hold a value that can be changed during the script execution. Following are the basic rules for naming a variable.

• You must use a letter as the first character.
• You can't use a space, period (.), exclamation mark (!), or the characters @, &, $, # in the name.
• Name can't exceed 255 characters in length.
• You cannot use Visual Basic reserved keywords as variable name.

Syntax
In VBA, you need to declare the variables before using them.

Dim <<variable_name>> As <<variable_type>>

Data Types

There are many VBA data types, which can be divided into two main categories, namely numeric and non-numeric data types.

Numeric Data Types

Following table displays the numeric data types and the allowed range of values.

Type	Range of Values
Byte	0 to 255
Integer	-32,768 to 32,767
Long	-2,147,483,648 to 2,147,483,648
Single	-3.402823E+38 to -1.401298E-45 for negative values 1.401298E-45 to 3.402823E+38 for positive values.
Double	-1.79769313486232e+308 to -4.94065645841247E-324 for negative values 4.94065645841247E-324 to 1.79769313486232e+308 for positive values.
Currency	-922,337,203,685,477.5808 to 922,337,203,685,477.5807
Decimal	+/- 79,228,162,514,264,337,593,543,950,335 if no decimal is use +/- 7.9228162514264337593543950335 (28 decimal places).

Non-Numeric Data Types

Following table displays the non-numeric data types and the allowed range of values.

Type	Range of Values
String (fixed length)	1 to 65,400 characters
String (variable length)	0 to 2 billion characters
Date	January 1, 100 to December 31, 9999
Boolean	True or False
Object	Any embedded object
Variant (numeric)	Any value as large as double
Variant (text)	Same as variable-length string

Example
Let us create a button and name it as 'Variables_demo' to demonstrate the use of variables.

Private Sub Variables_demo_Click() 
   Dim password As String 
   password = "Admin#1" 
  
   Dim num As Integer
   num = 1234 
  
   Dim BirthDay As Date 
   BirthDay = 30 / 10 / 2020 
  
   MsgBox "Passowrd is " & password & Chr(10) & "Value of num is " & num & Chr(10) 
      & "Value of Birthday is " & BirthDay  
End Sub

Output
Upon executing the script, the output will be as shown in the following screenshot.