How to check if a string is blank (empty, nothing, or contains only whitespace) in VB.NET

1 Answer

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Imports System

Class IsBlankOrEmpty
    Public Shared Function IsBlankOrEmptyMethod(ByVal str As String) As Boolean
        If String.IsNullOrEmpty(str) Then
            Return True
        End If

        For Each ch As Char In str

            If Not Char.IsWhiteSpace(ch) Then
                Return False
            End If
        Next

        Return True
    End Function

    Public Shared Sub Main()
        Dim test1 As String = Nothing
        Dim test2 As String = ""
        Dim test3 As String = "   "
        Dim test4 As String = "abc"
	
        Console.WriteLine("Test1: " & IsBlankOrEmptyMethod(test1))
        Console.WriteLine("Test2: " & IsBlankOrEmptyMethod(test2))
        Console.WriteLine("Test3: " & IsBlankOrEmptyMethod(test3))
        Console.WriteLine("Test4: " & IsBlankOrEmptyMethod(test4))
    End Sub
End Class



' run:
'
' Test1: True
' Test2: True
' Test3: True
' Test4: False
'

 



answered Jun 7, 2025 by avibootz
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