The VBA Array function is a built-in VBA function that allows you to store multiple values of different data types in a single array variable. This function is useful for organizing and manipulating large sets of data in your VBA code. With the Array function, you can create arrays of any data type, from text strings to numbers to objects.
VBA Array Function – Purpose, Syntax and Arguments
Purpose:
The Array function in VBA is used to create an array variable and assign values to it in a single line of code. This saves time and makes your code more efficient. It is also useful for creating dynamic arrays, where the size of the array is not known beforehand and may change during runtime.
Syntax:
The syntax for the Array function is as follows:
Array(item1, item2, item3, ...)
Arguments:
- item1, item2, item3, … : The items to be stored in the array. These can be of any data type.
Example:
Let’s say we have a list of employee names that we want to store in an array variable. We can use the Array function to create an array called “employeeNames” and assign the names to it, like this:
Sub ArrayExample()
Dim employeeNames As Variant
employeeNames = Array("John Smith", "Jane Doe", "Bob Johnson", "Mary Brown")
End Sub
In this example, we have created an array containing four items – the names of our employees. We have also declared the array variable as ‘Variant’, which means it can hold any type of data.
Remarks:
- The Array function can only be used to create one-dimensional arrays. For multidimensional arrays, you can use the Array statement or the ‘Dim’ statement with a specified number of dimensions.
- The Array function automatically resizes the array to accommodate the number of items passed to it. It also automatically assigns the correct data type to the array, based on the data types of the items passed to it.
- To access the items in an array, you can use the array name followed by the index number in parentheses. For example, to access the first item in the “employeeNames” array above, we would use “employeeNames(0)”.
Important Notes:
- The Array function is case-sensitive, so make sure to use proper capitalization when calling it.
- If you want to assign values to an existing array using the Array function, make sure to declare the array as a variant or use the ‘Dim’ statement with a specified number of dimensions before using the function.
VBA Array function is a useful tool for creating and working with arrays in your VBA code. It allows you to quickly and efficiently store multiple values in a single variable and access them easily. Make sure to keep in mind the important notes and best practices when using this function in your projects.
Understanding VBA Array Function with Examples
Example 1: Creating an Array
One of the most basic functions of VBA is the ability to create an array. An array is a collection of data values that are stored in a specific order. These values can be of any type, including strings, integers, and even objects. In VBA, arrays are declared using the Dim statement, followed by a variable name and parentheses enclosing the size of the array.
Dim myArray(5) As Integer
In the above code, we have declared an array named “myArray” with a size of 5. This means that the array can hold a total of 5 values, from index 0 to 4. It is important to note that arrays in VBA are zero-based, meaning the first element has an index of 0.
To add values to the array, we can use the For…Next loop to iterate through the array and assign values to each index.
For i = 0 to 4
myArray(i) = i
Next i
In the above code, we have assigned the values 0, 1, 2, 3, and 4 to each index of the array. You can also manually assign values to specific indexes using the following code:
myArray(0) = 10 myArray(1) = 20 myArray(2) = 30 myArray(3) = 40 myArray(4) = 50
Arrays can also be multidimensional, meaning they can have multiple rows and columns. To declare a multidimensional array, we use two sets of parentheses for the size of the array, separated by a comma. For example:
Dim myArray(3,2) As String
This declares an array with 3 rows and 2 columns, allowing us to store a total of 6 values. To add values to a multidimensional array, we use nested For…Next loops, where the outer loop controls the rows and the inner loop controls the columns.
For i = 0 to 2
For j = 0 to 1
myArray(i,j) = "Value " & (i+1) & (j+1)
Next j
Next i
This code assigns values to the array as “Value 11”, “Value 12”, “Value 21”, “Value 22”, “Value 31”, “Value 32”, in the respective rows and columns.
Example 2: Accessing Array Elements
After creating an array, we may need to access the values stored in it to manipulate or use in our code. There are two ways to access array elements in VBA:
1. Using a For…Next Loop:
For i = 0 to 4
MsgBox myArray(i)
Next i
This code uses a For…Next loop to iterate through the array and display the value stored at each index using the MsgBox function.
2. Using the Index Property:
MsgBox myArray(2)
This code simply displays the value stored in index 2 of the array using the Index property.
It is important to note that when accessing array elements using the Index property, we do not need to use parentheses after the array name or a loop, as we are specifically referring to a single element in the array.
Example 3: Changing Array Size
In some cases, we may need to change the size of an array during runtime. This can be done using the ReDim statement. For example:
ReDim myArray(10)
This code changes the size of the array to 10, adding 5 more indexes to the original array. However, it is important to note that using the ReDim statement will erase any data stored in the original array. To preserve the data, we can use the Preserve keyword:
ReDim Preserve myArray(10)
This code will keep the original data and resize the array to 10 indexes. It is also possible to resize multidimensional arrays using the same method, with the additional use of commas to specify the size of each dimension.
Example 4: Sorting Arrays
VBA also has a built-in function for sorting arrays called “Sort”. This function rearranges the data in an array in ascending order. For example:
Sort myArray
This code will rearrange the values in the array “myArray” in ascending order. However, it is important to note that the Sort function only works on one-dimensional arrays. To sort multidimensional arrays, we need to use a separate sorting algorithm or rearrange the data manually using nested loops.
Example 5: Reversing Arrays
Sometimes, we may need to reverse the order of values in an array. This can be done using a simple For…Next loop, as shown in the code below:
For i = 0 to 2
temp = myArray(i)
myArray(i) = myArray(4-i)
myArray(4-i) = temp
Next i
This code swaps the values in each index, starting from the beginning and moving towards the middle of the array, effectively reversing the order of the values.
Conclusion
The array function in VBA is a powerful tool that allows us to store and manipulate large sets of data. It is essential to have a good understanding of how arrays work and how to use them in our code to improve efficiency and organization. By using the examples discussed in this blog post, you can start working with arrays in VBA and make your code more dynamic and efficient.
