Array Size with UBound() and LBound()

UBound() returns the highest available subscript of an array dimension; it does not directly return the number of elements. Use it together with LBound() when you need the element count.

Highest index and loop limit

Dim myArray(3), i
myArray(0) = "UK"
myArray(1) = "USA"
myArray(2) = "Canada"
myArray(3) = "UAE"

Response.Write "Highest index = " & UBound(myArray)
For i = LBound(myArray) To UBound(myArray)
    Response.Write "<br>" & myArray(i)
Next

Here the highest index is 3 and the array contains four elements.

Multi-dimensional arrays

Dim arr(3, 4), totalElements
totalElements = (UBound(arr, 1) - LBound(arr, 1) + 1) * _
                (UBound(arr, 2) - LBound(arr, 2) + 1)
Response.Write "Total elements in the array: " & totalElements

Reusable array-size function

Function ArraySize(arr)
    ArraySize = UBound(arr) - LBound(arr) + 1
End Function

Dim arr(10)
Response.Write "Size of the array is: " & ArraySize(arr)

Loop and display the size

Dim arr(5), i, arraySize
For i = LBound(arr) To UBound(arr)
    arr(i) = i * 10
Next

arraySize = UBound(arr) - LBound(arr) + 1
Response.Write "Size of array: " & arraySize & "<br>"

For i = LBound(arr) To UBound(arr)
    Response.Write "Element " & i & " = " & arr(i) & "<br>"
Next

Resize a dynamic array

Dim arr()
ReDim arr(3)
arr(0) = "A"
arr(1) = "B"
arr(2) = "C"
arr(3) = "D"
Response.Write "Size before resizing: " & (UBound(arr) - LBound(arr) + 1) & "<br>"

ReDim Preserve arr(5)
arr(4) = "E"
arr(5) = "F"
Response.Write "Size after resizing: " & (UBound(arr) - LBound(arr) + 1) & "<br>"

For a one-dimensional array the count is UBound(array) - LBound(array) + 1. For multiple dimensions, calculate each dimension separately.

Subhendu Mohapatra

Author & Instructor at plus2net

I write and maintain practical tutorials on Python, PHP, SQL, JavaScript, HTML, jQuery, and web development at plus2net. The tutorials focus on clear explanations, working examples, and code that readers can test and adapt while learning.

About the author   Watch on YouTube

Connect: