CODEWITHSUNDEEP
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Tim
Tim

Reputation: 331

Array length with fixed index

I was wondering if there was anyway in Visual Basic to check the CURRENT length of an array that has been declared and initialized with a fixed number but may or may not have any data stored in in yet. e.g

Dim arrayStudent As String(3) = {}

is an array with 3 indexes but no current data, and if I used arrayStudent.length, then that is going to be "3" no matter what.

I'm trying to set up an if statement that will let the input textbox into my for-loop if the current length is less than 3.

Upvotes: 0

Views: 65

Answers (1)

Jon Skeet
Jon Skeet

Reputation: 1500903

There's no such concept as "current length". It has 3 elements from the start. All of them have a value of Nothing to start with, but the length is still 3.

If you're trying to count how many non-Nothing elements are in the array, you could use LINQ:

Dim count = arrayStudent.Count(Function(x) x IsNot Nothing)

But frankly you'd be better using a List(Of String) instead...

Note that as far as I can tell, your variable declaration is invalid to start with - but this works:

Public Class Test
    Public Shared Sub Main()
        Dim arrayStudent(3) As String
        Dim count = arrayStudent.Count(Function(x) x IsNot Nothing)
        Console.WriteLine(count)
        arrayStudent(1) = "Fred"
        count = arrayStudent.Count(Function(x) x IsNot Nothing)
        Console.WriteLine(count)
    End Sub
End Class

Upvotes: 4

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