Name
IsArray Function
Class
Microsoft.VisualBasic.Information
Syntax
IsArray(varname
)
-
varname
Use: Required
Data Type: Any variable
A variable that may be an array
Return Value
Boolean (True
or False
)
Description
Tests whether an object variable points to an array
Rules at a Glance
If the variable passed to IsArray
is an array or
contains an array, True
is returned; otherwise,
IsArray
returns False
.
Example
The following code displays True
:
Dim s( ) As Integer = {1, 2} Dim t As Object t = s MsgBox(IsArray(t))
Programming Tips and Gotchas
Due to the nature of Objects, it is not always obvious if an Object variable contains an array, especially if you have passed the variable to a function and the function may or may not have attached an array to the variable. Calling the array function
UBound
or trying to access an element in an array that does not exist will generate an error. In these situations, you should first use theIsArray
function to determine if you can safely process the array.An uninitialized array returns
False
. For example:Dim strArr( ) As String Console.WriteLine(IsArray(strArr)) ' Returns False
Array-like data structures, such as the
Collection
object, returnFalse
when passed to theIsArray
function.
VB .NET/VB 6 Differences
In VB 6, the IsArray
function returns
True
when passed an uninitialized array. In VB
.NET, it returns False
.
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