Why enums with default values are not working as expected in C#?

Question

I was going through Jon skeet website on C# Brain teasers http://www.yoda.arachsys.com/csharp/teasers.html. Why item "Baz" is showing in the output even though I declared default values for all items in enum

---eg:1

class Test
{

    enum Foo { Bar, Baz,bread, jam };

    const int One = 1;
    const int Une = 1;

    static void Main()
    {
        Foo f = 0;
        Console.WriteLine(f);
        Console.ReadLine();
    }
}
// output :Bar

--eg2

class Test
{
    enum Foo { Bar, Baz,bread=0, jam };

    const int One = 1;
    const int Une = 1;


    static void Main()
    {
        Foo f = 0;
        Console.WriteLine(f);
        Console.ReadLine();
    }
}
//output : Bar

--eg3

class Test
{
    enum Foo { Bar, Baz=0, bread=0, jam };

    const int One = 1;
    const int Une = 1;

    static void Main()
    {
        Foo f = 0;
        Console.WriteLine(f);
        Console.ReadLine();
    }
}
//output :Baz

--eg4

class Test
{
    enum Foo { Bar=0, Baz=0, bread=0, jam=0};

    const int One = 1;
    const int Une = 1;


    static void Main()
    {
        Foo f = 0;
        Console.WriteLine(f);
        Console.ReadLine();
    }
}
//output:Baz

Answer 1

Enums are just integers to .NET. Any time you think of them as a name (like ToString(), you're actually saying "try to find a defined enum label that matches the integer value, and tell me the name of that". In this case, you have multiple enum labels with the same integer value, so which name in WriteLine is undefined. Note that WriteLine here is ultimately doing f.ToString(), which applies the "find a value" logic from above.

For --eg5, I would propose: Foo f = (Foo)-1327861;. Perfectly valid in .NET terms, but doesn't match any enum definition. It doesn't have to.