Why can you have a comma at the end of a collection initializer?

Question

This one has always puzzled me, but i'm guessing there is a very sensible explanation of why it happens.

When you have a collection initializer the compiler allows a trailing comma, e.g.

new Dictionary<string, string>
{
    { "Foo", "Bar "},
};

and

new List<string>
{
    "Foo",
};

Anyone know why this trailing comma is allowed by the compiler?

Answer 1

Probably mainly for tools like code generators, where is it hugely convenient not to have to know if this is the first or last item. Arguably this shouldn't be a determining factor, but (having written such tools) I am grateful for it.

Answer 2

Similar reason to .NET Enumeration allows comma in the last field