VBA Asc Function

The VBA Asc Function is a built-in function used to return the ANSI character code (a unique numeric code assigned to each character) for the first character in a given string. This function is primarily used for converting text characters to their corresponding ASCII code value.

VBA Asc Function – Purpose, Syntax and Arguments

Syntax:

Asc(String)

Arguments:

• String: This is the required argument which takes a string or a single character as input. It represents the string for which the ASCII code of the first character is to be returned.

Example:

Suppose we have a string “Hello World!” and we want to find the ASCII code for the first character “H”. Below is a sample code using the Asc function.

Sub AscExample()
    Dim str As String
    str = "Hello World!"
    'Returns 72 (ASCII code for "H")
    MsgBox Asc(str)
End Sub

Remarks and Important Notes:

• The Asc function only returns the ASCII code for the first character in a given string. If the string contains multiple characters, only the first character will be considered for the calculation.
• The returned ASCII code is a unique numeric value assigned to each character based on the ASCII encoding system. It contains a range of numbers from 0 to 255.
• The function is not case sensitive, which means that the ASCII code for uppercase and lowercase letters will remain the same.
• If the string is empty, the Asc function will return 0.

VBA Asc function is a useful tool for converting string characters to their corresponding ASCII code. This function is commonly used in programming to perform various string operations and calculations. It is important to note that the function only returns the ASCII code for the first character in a given string and the returned value may vary depending on the encoding system used.

Understanding VBA Asc Function with Examples

Example 1: Finding the Ascii Code for a Single Character

Description: The ‘Asc’ function in VBA is used to find the Ascii code for a single character. This function takes a single argument, which is the character for which we want to find the Ascii code. The Ascii code is a numerical representation of the character according to the American Standard Code for Information Interchange (ASCII).

result = Asc("A")

1. The ‘Asc’ function takes the character “A” as an argument.
2. The function returns the Ascii code for “A” which is 65.
3. The value 65 is stored in the ‘result’ variable.

Explanation: In this example, the ‘Asc’ function is used to find the Ascii code for the character “A”. We first declare a variable called ‘result’ to store the return value of the function. Then we use the ‘Asc’ function with the argument “A” which is enclosed in double quotes. The function returns the Ascii code for “A” which is 65. The value 65 is then stored in the ‘result’ variable. This example shows how the ‘Asc’ function can be used to find the Ascii code for a single character.

Example 2: Finding the Ascii Code for the First Character in a String

Description: The ‘Asc’ function can also be used to find the Ascii code for the first character in a string. In this example, we will be using the ‘Asc’ function within a loop to find the Ascii code for each character in a string.

For i = 1 To Len(myString)
    code = Asc(Mid(myString, i, 1))
    Debug.Print code
Next i

1. In this code, we are using a ‘For’ loop to loop through each character in the string ‘myString’.
2. The function ‘Len’ is used to determine the length of the string, which is used as the end value for the loop.
3. In each iteration of the loop, the ‘Asc’ function is used to find the Ascii code for the character at the current position (i.e. i) in the string. We use the ‘Mid’ function to extract the character at position i.
4. The code is then stored in the variable ‘code’.
5. The ‘Debug.Print’ statement is used to print the value of ‘code’ in the immediate window.
6. This process continues until the loop reaches the end of the string.

Explanation: In this example, we are using the ‘Asc’ function within a ‘For’ loop to find the Ascii code for each character in a string. The ‘Len’ function is used to determine the length of the string and is used as the end value for the loop. In each iteration of the loop, the ‘Asc’ function is used to find the Ascii code for the character at the current position in the string. The code is then stored in the variable ‘code’ and printed in the immediate window. This example shows how the ‘Asc’ function can be used within a loop to find the Ascii code for each character in a string.

Example 3: Converting a String to an Array of Ascii Codes

Description: The ‘Asc’ function can also be used to convert a string to an array of Ascii codes. In this example, we will be using the ‘Asc’ function within a loop to add the Ascii codes of each character in a string to an array.

Dim myString As String
Dim i, j As Integer 
Dim codeArray() As Variant
myString = "Hello"
ReDim codeArray(1 To Len(myString))
For i = 1 To Len(myString)
    codeArray(i) = Asc(Mid(myString, i, 1))
Next i
For j = 1 To Len(myString)
    Debug.Print codeArray(j)
Next j

1. We first declare a string variable ‘myString’ and an integer variable ‘i’ and ‘j’.
2. Then we declare an array ‘codeArray’ of type variant.
3. The string “Hello” is assigned to the variable ‘myString’.
4. The ‘ReDim’ statement is used to redimension the array ‘codeArray’ with the size equal to the length of ‘myString’.
5. In the first ‘For’ loop, the ‘Asc’ function is used to add the Ascii codes of each character in the string ‘myString’ to the array ‘codeArray’.
6. In the second ‘For’ loop, the ‘Debug.Print’ statement is used to print the contents of the array ‘codeArray’ in the immediate window.

Explanation: In this example, we declare a string variable, an array and two integer variables. We then assign a string to the variable ‘myString’. Using the ‘Asc’ function within a ‘For’ loop, we add the Ascii codes of each character in the string to the array. The ‘ReDim’ statement is used to redimension the array with the size equal to the length of the string. In the second ‘For’ loop, the contents of the array are printed in the immediate window. This example shows how the ‘Asc’ function can be used to convert a string to an array of Ascii codes.

Example 4: Using Asc Function to Generate a Random Password

Description: We can also use the ‘Asc’ function to generate a random password in VBA. In this example, we will use the ‘Rnd’ function to generate a random number and then use the ‘Asc’ function to convert that number to an Ascii character.

Dim password As String
For i = 1 To 8
    randomNum = Int((90 - 65 + 1) * Rnd + 65)
    password = password & Chr(Asc(randomNum))
Next i
Debug.Print password

1. In this example, we declare a string variable ‘password’ to store the generated password.
2. We use a ‘For’ loop to generate 8 characters for the password.
3. The ‘Rnd’ function is used to generate a random number between 65 and 90 (characters A-Z) for each iteration of the loop.
4. The ‘Asc’ function is then used to convert the random number to its corresponding Ascii character.
5. The variable ‘password’ is concatenated with the generated character in each iteration of the loop.
6. The final generated password is then printed in the immediate window using the ‘Debug.Print’ statement.

Explanation: In this example, we are using the ‘Ascii’ function in combination with the ‘Rnd’ function to generate a random password. We use a loop to generate 8 characters for the password and in each iteration of the loop, a random number is generated using the ‘Rnd’ function. This random number is then converted to its corresponding Ascii character using the ‘Asc’ function and is concatenated with the password variable. This process repeats until the loop reaches its end, resulting in a random password. This example shows how the ‘Asc’ function can be used to generate a random password in VBA.

Conclusion:

In conclusion, the ‘Asc’ function in VBA is a very useful function that is used to find the Ascii code for a single character, the first character in a string, convert a string to an array of Ascii codes and to generate a random password. It is a simple but powerful function that can be used in various ways to manipulate characters and strings in VBA. The above examples demonstrate the different applications of the ‘Asc’ function, and it is recommended to practice and explore more on your own to fully understand its potential.