7.5.4 Member access

A member-access consists of a primary-expression or a predefined-type, followed by a "." token, followed by an identifier.

member-access:

primary-expression   .   identifier
predefined-type   .   identifier

predefined-type: one of

bool   byte   char   decimal   double   float   int   long
object   sbyte   short   string   uint   ulong   ushort

A member-access of the form E.I, where E is a primary-expression or a predefined-type and I is an identifier, is evaluated and classified as follows:

• If E is a namespace and I is the name of an accessible member of that namespace, then the result is that member and, depending on the member, is classified as a namespace or a type.
• If E is a predefined-type or a primary-expression classified as a type, and a member lookup (Section 7.3) of I in E produces a match, then E.I is evaluated and classified as follows:
  • If I identifies a type, then the result is that type.
  • If I identifies one or more methods, then the result is a method group with no associated instance expression.
  • If I identifies a static property, then the result is a property access with no associated instance expression.
  • If I identifies a static field:

    If the field is readonly and the reference occurs outside the static constructor of the class or struct in which the field is declared, then the result is a value, namely the value of the static field I in E.

    Otherwise, the result is a variable, namely the static field I in E.

  • If I identifies a static event:

    If the reference occurs within the class or struct in which the event is declared, and the event was declared without event-accessor-declarations (Section 10.7), then E.I is processed exactly as if I was a static field.

    Otherwise, the result is an event access with no associated instance expression.

  • If I identifies a constant, then the result is a value, namely the value of that constant.
  • If I identifies an enumeration member, then the result is a value, namely the value of that enumeration member.
  • Otherwise, E.I is an invalid member reference, and a compile-time error occurs.
• If E is a property access, indexer access, variable, or value, the type of which is T, and a member lookup (Section 7.3) of I in T produces a match, then E.I is evaluated and classified as follows:
  • First, if E is a property or indexer access, then the value of the property or indexer access is obtained (Section 7.1.1) and E is reclassified as a value.
  • If I identifies one or more methods, then the result is a method group with an associated instance expression of E.
  • If I identifies an instance property, then the result is a property access with an associated instance expression of E.
  • If T is a class-type and I identifies an instance field of that class-type:

    If the value of E is null, then a System.NullReferenceException is thrown.

    Otherwise, if the field is readonly and the reference occurs outside an instance constructor of the class in which the field is declared, then the result is a value, namely the value of the field I in the object referenced by E.

    Otherwise, the result is a variable, namely the field I in the object referenced by E.

  • If T is a struct-type and I identifies an instance field of that struct-type:

    If E is a value, or if the field is readonly and the reference occurs outside an instance constructor of the struct in which the field is declared, then the result is a value, namely the value of the field I in the struct instance given by E.

    Otherwise, the result is a variable, namely the field I in the struct instance given by E.

  • If I identifies an instance event:

    If the reference occurs within the class or struct in which the event is declared, and the event was declared without event-accessor-declarations (Section 10.7), then E.I is processed exactly as if I was an instance field.

    Otherwise, the result is an event access with an associated instance expression of E.

• Otherwise, E.I is an invalid member reference, and a compile-time error occurs.