Why C# Arrays type IsSerializable property is True?

Question

I was just curious why C# arrays return true for their IsSerializable property. Arrays do not have any Serializable attribute, and they also don't implement the ISerializable interface, so why is the IsSerializable property set to true?

When I try the below code, it outputs "True" in the console:

Console.WriteLine (new string[0].GetType().IsSerializable);

The output is:

True

Try it online

My .NET runtime version is 3.5.

Answer 1

Arrays does not have any Serializable attribute and also they aren't implement ISerializable interface

Array class, an implicit base class of C# arrays, has [SerializableAttribute]:

[SerializableAttribute]
[ComVisibleAttribute(true)]
public abstract class Array : ICloneable, IList, ICollection, 
    IEnumerable, IStructuralComparable, IStructuralEquatable

(reference)

It also appears that the compiler adds [SerializableAttribute] to the array type itself

foreach (var a in typeof(string[]).GetCustomAttributes(false)) {
    Console.WriteLine(a); // Prints "System.SerializableAttribute"
}

Passing false to GetCustomAttributes ensures that only attributes for this class, and not for its base classes, are returned.

Demo.