Variable is a named memory location used to hold a value that can be changed during the script execution. Below are the basic rules for naming a variable. Listed below are the 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.
- Cannot use Visual Basic reserved keywords as variable name.
Syntax
In VBA, we 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 grossly divided into two main categories namely numeric and non-numeric data types.
Numeric Data-Types
Below table displays the numeric data types and 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
Below table displays the Non-numeric data types and 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 demostrate 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 below.
