If a class’s properties have set accessors, the class is probably immutable.

Assume you have written a ToString method in a class, and created an instance of the class named object1. The following two statements are equivalent:MessageBox.Show(object1);MessageBox.Show(object1.ToString());

It is permissible to pass null as an argument to a reference type parameter in a method.

The following statement will cause a compiler error:int number = null;

The class header defines a class’s fields, properties, and methods.

If you try to pass a property to a ref or an out parameter, an error occurs.

To make a property read-only, omit the set accessor for the property.

Objects that are instances of a class cannot be stored in an array.

In C#, you are not allowed to use an uninitialized class field.

To make a property read-only, you must omit the get accessor for the property.