Structure Package
    Public Company As String
    Public Weight As Double
End Structure

Sub SumEx1()
    ' Create a list of Package values.
    Dim packages As New List(Of Package)(New Package() _
         {New Package With {.Company = "Coho Vineyard", .Weight = 25.2}, _
          New Package With {.Company = "Lucerne Publishing", .Weight = 18.7}, _
          New Package With {.Company = "Wingtip Toys", .Weight = 6.0}, _
          New Package With {.Company = "Adventure Works", .Weight = 33.8}})

    ' Sum the values from each item's Weight property.
    Dim totalWeight As Double = packages.Sum(Function(pkg) _
                                                 pkg.Weight)

    ' Display the result.
    MsgBox("The total weight of the packages is: " & totalWeight)
End Sub

' This code produces the following output:
'
' The total weight of the packages is: 83.7

class Package
{
    public string Company { get; set; }
    public double Weight { get; set; }
}

public static void SumEx1()
{
    List<Package> packages =
        new List<Package> 
            { new Package { Company = "Coho Vineyard", Weight = 25.2 },
              new Package { Company = "Lucerne Publishing", Weight = 18.7 },
              new Package { Company = "Wingtip Toys", Weight = 6.0 },
              new Package { Company = "Adventure Works", Weight = 33.8 } };

    double totalWeight = packages.Sum(pkg => pkg.Weight);

    Console.WriteLine("The total weight of the packages is: {0}", totalWeight);
}

/*
 This code produces the following output:

 The total weight of the packages is: 83.7
*/