C# language specifications

C# is a modern, object-oriented language that enables programmers to quickly build a wide range of applications for the next-generation Microsoft .NET platform. Because of its elegant design, which combines the raw power of C++ with the simplicity of Visual Basic, C# is a great choice for architecting a wide range of components-from high-level business objects to system-level applications. Get a head start on developing in C# with this first printed look at the complete C# language specification. This MSDN guide includes the essential features and basic concepts of the C# language, plus in-depth analysis of the lexical structure of the language. It also provides details about types, variables, conversions, expressions, statements, namespaces, classes, structures, arrays, interfaces, enumerators, delegates, exceptions, and attributes; information on how C# simplifies coding by omitting pointers as a data type-or lets you get closer to the hardware by declaring and operating on pointers in unsafe code-a list of attributes used for creating programs that interoperate with COM programs, plus a list of other key references.

Other new and available Microsoft.NET related titles in the MSDN Series of substantial interest to professional developers includes:

• Web Applications in the Microsoft.NET Framework
• Microsoft Visual Studio.NET
• The Microsoft.NET Framework
• Microsoft .NET Framework Developer Specifications

Table of Contents

Preface ..... xvii

Who Is This Book For? ..... xvii

What's in This Book? ..... xvii

A Warning ..... xviii

About MSDN ..... xviii

1: Introduction ..... 1

1.1: Getting started ..... 1

1.2: Types ..... 2

1.3: Variables and parameters ..... 12

1.4: Automatic memory management ..... 17

1.5: Expressions ..... 20

1.6: Statements ..... 21

1.7: Classes ..... 24

1.8: Structs ..... 40

1.9: Interfaces ..... 41

1.10: Delegates ..... 43

1.11: Enums ..... 44

1.12: Namespaces and assemblies ..... 45

1.13: Versioning ..... 48

1.14: Attributes ..... 51

2: Lexical structure ..... 53

2.1: Phases of translation ..... 53

2.2: Grammar notation ..... 53

2.3: Lexical analysis ..... 54

2.4: Tokens ..... 57

2.5: Pre-processing directives ..... 66

3: Basic concepts ..... 75

3.1: Program Startup ..... 75

3.2: Program Termination ..... 76

3.3: Declarations ..... 76

3.4: Members ..... 79

3.5: Member access ..... 81

3.6: Signatures and overloading ..... 88

3.7: Scopes ..... 89

3.8: Namespace and type names ..... 95

4: Types ..... 99

4.1: Value types ..... 99

4.2: Reference types ..... 107

4.3: Boxing and unboxing ..... 109

5: Variables ..... 113

5.1: Variable categories ..... 113

5.2: Default values ..... 116

5.3: Definite assignment ..... 117

5.4: Variable references ..... 120

6: Conversions ..... 121

6.1: Implicit conversions ..... 121

6.2: Explicit conversions ..... 123

6.3: Standard conversions ..... 127

6.4: User-defined conversions ..... 127

7: Expressions ..... 131

7.1: Expression classifications ..... 131

7.2: Operators ..... 133

7.3: Member lookup ..... 139

7.4: Function members ..... 140

7.5: Primary expressions ..... 150

7.6: Unary expressions ..... 172

7.7: Arithmetic operators ..... 176

7.8: Shift operators ..... 183

7.9: Relational operators ..... 185

7.10: Logical operators ..... 193

7.11: Conditional logical operators ..... 194

7.12: Conditional operator ..... 196

7.13: Assignment operators ..... 197

7.14: Expression ..... 201

7.15: Constant expressions ..... 202

7.16: Boolean expressions ..... 203

8: Statements ..... 205

8.1: End points and reachability ..... 205

8.2: Blocks ..... 207

8.3: The empty statement ..... 208

8.4: Labeled statements ..... 209

8.5: Declaration statements ..... 210

8.6: Expression statements ..... 212

8.7: Selection statements ..... 212

8.8: Iteration statements ..... 218

8.9: Jump statements ..... 223

8.10: The try statement ..... 229

8.11: The checked and unchecked statements ..... 232

8.12: The lock statement ..... 232

8.13: The using statement ..... 233

9: Namespaces ..... 237

9.1: Compilation units ..... 237

9.2: Namespace declarations ..... 238

9.3: Using directives ..... 239

9.4: Namespace members ..... 245

9.5: Type declarations ..... 245

10: Classes ..... 247

10.1: Class declarations ..... 247

10.2: Class members ..... 251

10.3: Constants ..... 255

10.4: Fields ..... 257

10.5: Methods ..... 263

10.6: Properties ..... 282

10.7: Events ..... 292

10.8: Indexers ..... 297

10.9: Operators ..... 301

10.10: Instance constructors ..... 304

10.11: Static constructors ..... 311

10.12: Destructors ..... 314

11: Structs ..... 315

11.1: Struct declarations ..... 315

11.2: Struct members ..... 317

11.3: Class and struct differences ..... 317

11.4: Struct examples ..... 321

12: Arrays ..... 325

12.1: Array types ..... 325

12.2: Array creation ..... 326

12.3: Array element access ..... 327

12.4: Array members ..... 327

12.5: Array covariance ..... 327

12.6: Array initializers ..... 328

13: Interfaces ..... 331

13.1: Interface declarations ..... 331

13.2: Interface members ..... 333

13.3: Fully qualified interface member names ..... 338

13.4: Interface implementations ..... 339

14: Enums ..... 351

14.1: Enum declarations ..... 351

14.2: Enum modifiers ..... 352

14.3: Enum members ..... 352

14.4: Enum values and operations ..... 355

15: Delegates ..... 357

15.1: Delegate declarations ..... 357

15.2: Delegate instantiation ..... 358

15.3: Multi-cast delegates ..... 359

15.4: Delegate invocation ..... 359

16: Exceptions ..... 361

16.1: Causes of exceptions ..... 361

16.2: The System.Exception class ..... 361

16.3: How exceptions are handled ..... 362

16.4: Common Exception Classes ..... 363

17: Attributes ..... 365

17.1: Attribute classes ..... 365

17.2: Attribute specification ..... 368

17.3: Attribute instances ..... 371

17.4: Reserved attributes ..... 373

A: Unsafe code ..... 379

A.1: Unsafe contexts ..... 379

A.2: Pointer types ..... 381

A.3: Fixed and moveable variables ..... 383

A.4: Pointer conversions ..... 384

A.5: Pointers in expressions ..... 384

A.6: The fixed statement ..... 390

A.7: Stack allocation ..... 393

A.8: Dynamic memory allocation ..... 394

B: Interoperability ..... 397

B.1: The ComAliasName attribute ..... 397

B.2: The ComImport attribute ..... 397

B.3: The ComRegisterFunction attribute ..... 398

B.4: The ComSourceInterfaces attribute ..... 398

B.5: The ComUnregisterFunction attribute ..... 399

B.6: The ComVisible attribute ..... 399

B.7: The DispId attribute ..... 400

B.8: The DllImport attribute ..... 400

B.9: The FieldOffset attribute ..... 401

B.10: The Guid attribute ..... 402

B.11: The HasDefaultInterface attribute ..... 402

B.12: The ImportedFromTypeLib attribute ..... 403

B.13: The In and Out attributes ..... 403

B.14: The IndexerName attribute ..... 404

B.15: The InterfaceType attribute ..... 404

B.16: The MarshalAs attribute ..... 405

B.17: The NoIDispatch attribute ..... 405

B.18: The PreserveSig attribute ..... 406

B.19: The StructLayout attribute ..... 406

B.20: The TypeLibFunc attribute ..... 407

B.21: The TypeLibType attribute ..... 407

B.22: The TypeLibVar attribute ..... 407

B.23: Supporting enums ..... 408

C: References ..... 411