Dim arr1 As Integer() = {1, 2, 3}
        Dim arr2 As Integer() = {4, 5, 6}
        Dim arr3 As Integer() = {7, 8, 9}
 
        Dim Result As Integer() =
            arr1.
            Concat(arr2).
            Concat(arr3).
            ToArray
 
        MsgBox(String.Join(", ", Result)) ' Result = {1, 2, 3, 4, 5, 6, 7, 8, 9}

        Dim arr1 As Array = {1, 2, 3}
        Dim arr2 As Array = {4, 5, 6}
        Dim arr3 As Array = {7, 8, 9}
 
        Dim Result As Integer() =
            arr1.Cast(Of Integer).
            Concat(arr2.Cast(Of Integer)).
            Concat(arr3.Cast(Of Integer)).
            ToArray
 
        MsgBox(String.Join(", ", Result)) ' Result = {1, 2, 3, 4, 5, 6, 7, 8, 9}

Dim Result As Integer() = arr1.Concat(arr2).Concat(arr3).Distinct.ToArray