Strings, or text data, play a significant role in data processing and analysis in Excel VBA. Whether you’re cleaning data, extracting specific information, or formatting text, mastering string manipulation techniques is essential. In this article, we’ll explore various aspects of string in Excel VBA, explaining each concept with practical examples.

1. Declaring and Initializing Strings

Before you manipulate strings, you need to declare and initialize them. In VBA, you can declare a string variable using the Dim statement.

Dim myString As String
myString = "Hello, vmlogger!"

2. How to do string Concatenation

String concatenation is the process of combining two or more strings. In Excel VBA, you can use the & operator or the + operator for this purpose.

Dim firstName As String
Dim lastName As String
Dim fullName As String

firstName = "John"
lastName = "Doe"

' Using the & operator
fullName = firstName & " " & lastName

' Using the + operator
fullName = firstName + " " + lastName

In VBA, there is a difference between the & operator and the + operator when it comes to string concatenation.

2.1 Concatenate string using & Operator (Ampersand):

This operator is specifically used for string concatenation. When you use & to concatenate strings, VBA ensures that the operands are treated as strings, and it performs the concatenation accordingly. It’s the preferred operator for joining strings in VBA.

Example:

Dim str1 As String
Dim str2 As String

str1 = "Hello, "
str2 = "World!"
Dim result As String
result = str1 & str2

2.2 Concatenate string using + Operator (Plus Sign):

The + operator is used for arithmetic addition. While it can also be used for string concatenation, it may not be as reliable or straightforward as the & operator. Using +< for concatenation may lead to unexpected results if the operands are not explicitly declared as strings.

Example:

Dim str1 As String
Dim str2 As String

str1 = "Hello, "
str2 = "World!"
Dim result As String
result = str1 + str2

3. How to get length of a String in Excel VBA

To determine the length of a string, you can use the Len function.

Dim myString As String
myString = "Hello, World!"
Dim length As Integer
length = Len(myString)

4. How to extract Substring from a String

To extract a substring from a larger string, you can use following three functions: Mid(), Left() and Right().

4.1 Substring using Mid() Function

This function requires the starting position and the length of the substring.

Dim originalString As String
originalString = "This is a sample string"
Dim subString As String
subString = Mid(originalString, 6, 6)

5. How to split a delimitted string in to array

You can split a string into an array of substrings using the Split function. This is useful when dealing with delimited data.

Dim data As String
data = "Apple,Orange,Banana"
Dim items() As String
items = Split(data, ",")

6. How to convert a string case to upper case or lower case

VBA provides functions for converting the case of strings. You can use UCase for uppercase and LCase for lowercase.

Dim originalString As String
originalString = "Hello, World!"
Dim upperString As String
Dim lowerString As String

upperString = UCase(originalString) 
lowerString = LCase(originalString)

7. How to Trim Whitespace from a string

The Trim function removes leading and trailing spaces from a string, making it useful for cleaning data.

Dim originalString As String
originalString = "    Trim this text     "
Dim trimmedString As String
trimmedString = Trim(originalString)

8. How to replace a part of string

You can replace one substring with another using the Replace function. Note: String is immutable. That means, you can not change the value of a string instead it creates another string with the replaced value.

Dim originalString As String
originalString = "Replace the old text with new text."
Dim updatedString As String
updatedString = Replace(originalString, "old text", "new text")

9. How to do string Comparisons

To compare two strings for equality, you can use the StrComp function. It returns 0 if the strings are equal.

Dim string1 As String
Dim string2 As String

string1 = "apple"
string2 = "Apple"
Dim result As Integer
result = StrComp(string1, string2, vbTextCompare)

10. How to search a String or substring

To find the position of a substring within a string, you can use the InStr function.

Dim originalString As String
originalString = "Find me in this text."

Dim position As Integer
position = InStr(originalString, "me")
' position is 6

11. Search in string using Regular Expressions

Excel VBA also supports regular expressions for advanced string manipulation. You can use the RegExp object to work with regular expressions.

Dim regex As Object
Set regex = CreateObject("VBScript.RegExp")

Dim pattern As String
pattern = "\d+" ' Matches one or more digits

Dim inputString As String
inputString = "123abc456def"

' Perform the regular expression search
regex.Global = True
regex.IgnoreCase = False
regex.Pattern = pattern

Dim matches As Object
Set matches = regex.Execute(inputString)

' Loop through the matches
For Each match In matches
    Debug.Print match.Value ' Outputs: 123, 456
Next match

12. String Formatting

You can format strings with placeholders using the Format function. This is helpful for creating dynamic messages.

Dim name As String
name = "John"
Dim age As Integer
age = 30

Dim message As String
message = "Hello, my name is {0}, and I am {1} years old."
message = Format(message, name, age)

13. Iterate through each letters of a String

You can loop through the characters in a string using a For loop. Basically strings are an array of characters.

Dim originalString As String
originalString = "Loop Me"

Dim i As Integer
For i = 1 To Len(originalString)
    Debug.Print Mid(originalString, i, 1)
Next i