Declaring and assigning strings

Remarks#

Strings are a Reference type and are central to most programming tasks. Strings are assigned text, even if the text happens to be numeric. Strings can be zero-length, or any length up to 2GB. Modern versions of VBA store Strings internally using a Byte array of Multi-Byte Character Set bytes (an alternative to Unicode).

Declare a string constant

Const appName As String = "The App For That"

Declare a variable-width string variable

Dim surname As String 'surname can accept strings of variable length
surname = "Smith"
surname = "Johnson"

Declare and assign a fixed-width string

'Declare and assign a 1-character fixed-width string
Dim middleInitial As String * 1 'middleInitial must be 1 character in length
middleInitial = "M"

'Declare and assign a 2-character fixed-width string `stateCode`,
'must be 2 characters in length
Dim stateCode As String * 2
stateCode = "TX"

Declare and assign a string array

'Declare, dimension and assign a string array with 3 elements
Dim departments(2) As String
departments(0) = "Engineering"
departments(1) = "Finance"
departments(2) = "Marketing"

'Declare an undimensioned string array and then dynamically assign with
'the results of a function that returns a string array
Dim stateNames() As String
stateNames = VBA.Strings.Split("Texas;California;New York", ";")

'Declare, dimension and assign a fixed-width string array
Dim stateCodes(2) As String * 2
stateCodes(0) = "TX"
stateCodes(1) = "CA"
stateCodes(2) = "NY"

Assign specific characters within a string using Mid statement

VBA offers a Mid function for returning substrings within a string, but it also offers the Mid Statement which can be used to assign substrings or individual characters withing a string.

The Mid function will typically appear on the right-hand-side of an assignment statement or in a condition, but the Mid Statement typically appears on the left hand side of an assignment statement.

Dim surname As String
surname = "Smith"

'Use the Mid statement to change the 3rd character in a string
Mid(surname, 3, 1) = "y"
Debug.Print surname

'Output:
'Smyth

Note: If you need to assign to individual bytes in a string instead of individual characters within a string (see the Remarks below regarding the Multi-Byte Character Set), the MidB statement can be used. In this instance, the second argument for the MidB statement is the 1-based position of the byte where the replacement will start so the equivalent line to the example above would be MidB(surname, 5, 2) = "y".

Assignment to and from a byte array

Strings can be assigned directly to byte arrays and visa-versa. Remember that Strings are stored in a Multi-Byte Character Set (see Remarks below) so only every other index of the resulting array will be the portion of the character that falls within the ASCII range.

Dim bytes() As Byte
Dim example As String

example = "Testing."
bytes = example             'Direct assignment.

'Loop through the characters. Step 2 is used due to wide encoding.
Dim i As Long
For i = LBound(bytes) To UBound(bytes) Step 2
    Debug.Print Chr$(bytes(i))  'Prints T, e, s, t, i, n, g, .
Next

Dim reverted As String
reverted = bytes            'Direct assignment.
Debug.Print reverted        'Prints "Testing."