UBoundfunction

Returns the upper bound of an array's dimension

Syntax

Declare Function UBound ( array() As Any, ByVal dimension As Integer = 1 ) As Integer

Parameters

Name		Description
`array`		an array of any type
`dimension`		the dimension to get upper bound of

Return value

Returns the upper bound of an array's dimension.

Description

UBound returns the largest value that can be used as an index into a particular dimension of an array.

Array dimensions are numbered from one (1) to n, where n is the total number of dimensions. If dimension is not specified, UBound will return the upper bound of the first dimension.

If dimension is zero (0), UBound returns n, the number of dimensions in the array. For any other dimension values outside of the valid range 1..n, the result is -1. This can be used to detect the number of dimensions of variable-length arrays, and in combination with the result of Lbound() for such cases, whether a given dimension exists, or whether the array is empty (zero dimensions). See the LBound page for more information.

Remarks

Usage



result = UBound( array [, dimension ] )

Example

Dim array(-10 To 10, 5 To 15, 1 To 2) As Integer



Print UBound(array) 'returns 10

Print UBound(array, 2) 'returns 15

Print UBound(array, 3) 'returns 2

'' determining the size of an array

Dim As Short array(0 To 9)

Dim As Integer arraylen, arraysize



arraylen = UBound(array) - LBound(array) + 1

arraysize = arraylen * SizeOf( Short )



Print "Number of elements in array:", arraylen    '10

Print "Number of bytes used in array:", arraysize '10 * 2 = 20

'' determining the size of a multi-dimensional array

Dim As Long array4D(1 To 2, 1 To 3, 1 To 4, 1 To 5)

Dim As Integer arraylen, arraysize





arraylen = (UBound(array4D, 4) - LBound(array4D, 4) + 1) _

         * (UBound(array4D, 3) - LBound(array4D, 3) + 1) _

         * (UBound(array4D, 2) - LBound(array4D, 2) + 1) _

         * (UBound(array4D, 1) - LBound(array4D, 1) + 1)



arraysize = arraylen * SizeOf( Long )



Print "Number of elements in array:", arraylen    '2 * 3 * 4 * 5 = 120

Print "Number of bytes used in array:", arraysize '120 * 4 = 480

'' determining whether an array is empty

Dim array() As Integer



Print "lbound: "; LBound( array ), "ubound: "; UBound( array )  ''  0 and -1



If LBound( array ) > UBound( array ) Then

    Print "array is empty"

Else

    Print "array is not empty"

End If

Sub printArrayDimensions( array() As Integer )

    Print "dimensions: " & UBound( array, 0 )



    '' For each dimension...

    For d As Integer = LBound( array, 0 ) To UBound( array, 0 )

        Print "dimension " & d & ": " & LBound( array, d ) & " to " & UBound( array, d )

    Next

End Sub



Dim array() As Integer

printArrayDimensions( array() )



Print "---"



ReDim array(10 To 11, 20 To 22)

printArrayDimensions( array() )

Reference

Documented in KeyPgUbound.html