What is the Difference Between `new object()` and `new {}` in C#?

Question

First of all i searched on this and i found the following links on Stack Overflow:

• Is there any difference between `new object()` and `new {}` in c#?

Answer 1

To see the difference between new Object() and new {} and new Object(){}... why don't we just find out?

Console.WriteLine(new Object().GetType().ToString());
Console.WriteLine(new Object() { }.GetType().ToString());
Console.WriteLine(new { }.GetType().ToString());

The first two are just different ways of creating an Object and prints System.Object. The third is actually an anonymous type and prints <>f__AnonymousType0.

I think you might be getting confused by the different uses of '{}'. Off the top of my head it can be used for:

1. Statement blocks.
2. Object/Collection/Array initialisers.
3. Anonymous Types

So, in short object data = new { }; does not create a new object. It creates a new AnonymousType which, like all classes, structures, enumerations, and delegates inherits Object and therefor can be assigned to it.

---

As mentioned in comments, when returning anonymous types you still have declare and downcast them to Object. However, they are still different things and have some implementation differences for example:

static void Main(string[] args)
{
    Console.WriteLine(ReturnO(true).ToString());  //"{ }"
    Console.WriteLine(ReturnO(false).ToString());  // "System.Object"

    Console.WriteLine(ReturnO(true).Equals(ReturnO(true)));  //True
    Console.WriteLine(ReturnO(false).Equals(ReturnO(false)));  //False
    Console.WriteLine(ReturnO(false).Equals(ReturnO(true)));  //False

    Console.WriteLine(ReturnO(true).GetHashCode());  //0
    Console.WriteLine(ReturnO(false).GetHashCode());  //37121646

    Console.ReadLine();
}

static object ReturnO(bool anonymous)
{
    if (anonymous) return new { };
    return new object();
}