How does serialization work without constructors?

I'm not sure how this piece of code works.

    [Serializable]
    class Blah
    {
        public Blah(int value)
        {
            this.value = value;
        }

        public int value;
    }

        开发者_StackOverflowBinaryFormatter b = new BinaryFormatter();
        Blah blah = new Blah(4);
        MemoryStream s = new MemoryStream();
        b.Serialize(s, blah);
        s.Seek(0, SeekOrigin.Begin);
        blah = null;
        blah = (Blah)b.Deserialize(s);

As I don't have a parameterless constructor, it seems strange that the deserializer can create a new instance of Blah.

The deserialization process uses FormatterServices.GetUninitializedObject which gets an object without calling any constructor.

The serializer doesn't call a constructor when it deserializes an object. The values of the fields are set directly. It doesn't need to create the object (via new) it just creates storage, fills it, and casts it as a Blah type.

BinaryFormatter uses voodoo method called FormatterServices.GetUninitializedObject:

...the object is initialized to zero and no constructors are run