What is it called when an object is initialized without a type?

Question

I've only encountered this a handful of times, and I don't understand it entirely yet, but I feel the need to research what's actually going on here behind the scenes.

I recognize that it is creating a new instance of an object, but the type has not been specified.

var myObject = new {
    SomeProperty = "ABC",
    SomeOtherProperty = true
};

It also works when you swap out var for object or dynamic. However, with that in mind, I can't really find what it's called in order to research it. I believe it is referred to as a pseudo-class or pseudo-object but I can't find any actual documentation on it.

I've performed several Google searches on the topic (here's the latest), and even reviewed a few related SO posts (here's one about initialization), but I'm still not finding the answer.

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What is this actually called?

Answer 1

Its called an anonymous type, and its instantiated directly.

Instantiation of anonymous types

To create an instance of an anonymous type, use the new operator and object initializer syntax:

var example = new { Greeting = "Hello", Name = "World" };
Console.WriteLine($"{example.Greeting}, {example.Name}!");