readonly fields can only be assigned in a class constructor. If a class has a field that’s not marked readonly but is
only set in the constructor, it could cause confusion about the field’s intended use. To avoid confusion, such fields should be marked
readonly to make their intended use explicit, and to prevent future maintainers from inadvertently changing their use.
Exceptions
- Fields declared in classes marked with the
Serializable attribute.
- Fields declared in
partial classes.
- Fields with attributes are ignored.
- Fields of type
struct that are not primitive or pointer types are also ignored because of possible unwanted behavior.