VBA Hex Function

The VBA Hex function is used to convert a number into its equivalent hexadecimal value. Hexadecimal, also known as base 16, is a numbering system that uses 16 different symbols, 0-9 and A-F, to represent numbers. This function takes in a decimal number as an input and returns a string containing the hexadecimal representation of that number.

VBA Hex Function – Purpose, Syntax and Arguments

Purpose:

The Hex function is useful when working with numerical data that needs to be converted into a format that is more easily readable and manageable. It is also helpful when working with computer memory addresses, file formats, and RGB color codes, as these values are typically represented in hexadecimal format.

Syntax:

Hex(number)

Arguments:

• number: This is a required argument and can be any valid numerical expression that you want to convert into a hexadecimal value.

Example:

Suppose we have a cell in Excel with the value 255, and we want to convert it into its hexadecimal representation using the Hex function. The code would look like this:

Sub convertToHex()
    Dim dec As Integer
    Dim hex As String
    
    'assign value from cell to variable
    dec = Range("A1").Value
    
    'use Hex function to convert decimal to hexadecimal
    hex = Hex(dec)
    
    'print result in immediate window
    Debug.Print dec, "in hexadecimal is", hex
End Sub

The output in the immediate window would be: 255 in hexadecimal is FF.

Remarks and Important Notes:

• The Hex function returns the hexadecimal value as a string, so it cannot be used in calculations without first converting it back to a number.
• If the number provided is not an integer, the function will round down to the nearest integer before converting it to hexadecimal.
• If the number provided is a negative value, the function will first convert it to its positive equivalent before converting it to hexadecimal.
• If the value provided is not a valid number, the function will return a #VALUE error.
• The Hex function only works with decimal numbers, so binary, octal, or any other numerical base cannot be converted using this function.

The VBA Hex function is a simple but powerful tool that allows for easy conversion between decimal and hexadecimal values. Its usefulness lies in its ability to make numerical data more readable and manageable, especially when working with computer memory and file formats. However, it is important to keep in mind that this function only works with decimal numbers and returns a string value, so it may not be suitable for all types of numerical calculations.

Understanding VBA Hex Function with Examples

Example 1: Converting a Decimal Number to a Hexadecimal Number

Dim num As Integer
num = 100

Dim hexNum As String
hexNum = Hex(num)

Explanation:
In this example, we first declare a variable ‘num’ and assign it a value of 100. Then, we declare another variable ‘hexNum’ and use the VBA Hex function to convert the decimal number stored in ‘num’ to its hexadecimal equivalent. The resulting hexadecimal number is then assigned to the variable ‘hexNum’.
The Hex function in VBA takes a decimal number as its parameter and returns a string representing the hexadecimal value of the number. In our example, ‘num’ holds the decimal value 100 which is equal to the hexadecimal value of 64. Therefore, the variable ‘hexNum’ is assigned a string value of “64” after the VBA Hex function is applied.

Example 2: Converting a String to a Hexadecimal Number

Dim str As String
str = "Hello World!"

Dim hexStr As String
hexStr = Hex(str)

Explanation:
In this example, we declare a string variable ‘str’ and assign it a value of “Hello World!”. As we know, strings cannot be directly converted to hexadecimal numbers since they are not numeric values. However, the VBA Hex function allows us to convert strings to their hexadecimal representation.
When the Hex function is applied to a string, it first converts each character in the string to its ASCII code and then converts the resulting ASCII values to their hexadecimal equivalent. The variable ‘hexStr’ in our example will be assigned a value of “48656C6C6F20576F726C6421” which is the hexadecimal representation of the string “Hello World!”.

Example 3: Converting a Hexadecimal Number to a Decimal Number

Dim hexNum As String
hexNum = "A1B"

Dim num As Integer
num = CInt("&h" & hexNum)

Explanation:
This example shows how we can use the VBA Hex function to convert a hexadecimal number back to its decimal representation. First, we declare a string variable ‘hexNum’ and assign it a value of “A1B”. Then, we declare an integer variable ‘num’ and use the ‘CInt’ function along with the string concatenation operator ‘&’ to convert the hexadecimal string to an integer.
The ‘CInt’ function in VBA converts a string to an integer, and the prefix “&h” is used to indicate that the string is a hexadecimal value. This tells the VBA compiler to interpret the string as a hexadecimal number instead of a decimal number. Therefore, the variable ‘num’ is assigned a value of 2587, which is the decimal equivalent of the hexadecimal number “A1B”.

Example 4: Using the VBA Hex Function in a Loop

Dim i As Integer
For i = 1 To 10
Debug.Print Hex(i)
Next i

Output:

1
2
3
4
5
6
7
8
9
A

Explanation:
In this example, we are using the VBA Hex function inside a loop to print the hexadecimal representation of numbers from 1 to 10. The loop runs 10 times, and in each iteration, the Hex function is called with the loop variable ‘i’ as its parameter. This allows us to print the hexadecimal equivalent of all the numbers in the loop.
The ‘Debug.Print’ statement in VBA is used to print the result to the immediate window. As we can see in the output, the hexadecimal numbers are represented as strings starting from 1 to A which corresponds to the decimal numbers 1 to 10.

Example 5: Using the VBA Hex Function with Negative Numbers

Dim num As Integer
num = -100

Dim hexNum As String
hexNum = Hex(num)

Explanation:
The VBA Hex function can also be used to convert negative numbers to their hexadecimal representation. In this example, we declare a variable ‘num’ and assign it a value of -100. When the Hex function is applied to this variable, it will return the hexadecimal representation of -100 which is “FFFFFF9C”.
This behavior might seem odd, but it is a result of how negative numbers are represented in binary. When a negative number is converted to its binary representation, it gets converted to a two’s complement representation which has 2^n – 1 as its maximum value where n is the number of bits. In our example, the length of an integer variable in VBA is 4 bytes which is equivalent to 32 bits. Therefore, the maximum value that can be stored in an integer variable is 2^32 – 1 which is 4294967295. When this value is added to -100, we get 4294967195 which is the two’s complement representation of -100. When the VBA Hex function is applied to this value, it returns its hexadecimal representation which is “FFFFFF9C”.
In conclusion, the VBA Hex function is a versatile function that can be used to convert decimal numbers and strings to their hexadecimal representation and vice versa. It is particularly useful when working with binary data or when performing bitwise operations in VBA. Understanding this function can help in writing more efficient and robust code in VBA.