ECMA-334: 11.1 Value types

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C# Language Specification

11. Types 11.1 Value types 11.1.1 System.ValueType type 11.1.2 Default constructors 11.1.3 Struct types 11.1.4 Simple types 11.1.5 Integral types 11.1.6 Floating point types 11.1.7 decimal type 11.1.8 bool type 11.1.9 Enumeration types

© 2006 ECMA International

11.1 Value types

A value type is either a struct type or an enumeration type. C# provides a set of predefined struct types called the simple types. The simple types are identified through reserved words.

value-type:

struct-type

enum-type

struct-type:

type-name

simple-type

nullable-type

simple-type:

numeric-type

bool

numeric-type:

integral-type

floating-point-type

decimal

integral-type:

sbyte

byte

short

ushort

int

uint

long

ulong

char

floating-point-type:

float

double

enum-type:

type-name

nullable-type:

non-nullable-value-type ?

non-nullable-value-type:

enum-type

type-name

simple-type

All value types implicitly inherit from class object. It is not possible for any type to derive from a value type, and value types are thus implicitly sealed (§17.1.1.2).

A variable of a value type always contains a value of that type. Unlike reference types, it is not possible for a value of a value type to be null, or to reference an object of a more derived type.

Assignment to a variable of a value type creates a copy of the value being assigned. This differs from assignment to a variable of a reference type, which copies the reference but not the object identified by the reference.