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97sbyte and byte ranges
98short and ushort
99int and uint arithmetic
100long and ulong
101nint and nuint native integers
102Int128 and UInt128
103Half floating point
104float and double IEEE 754
105decimal precision and scaling
106char and UTF-16 code units
107bool and logical operators
108Checked and unchecked contexts
109Integer overflow behavior
110Implicit numeric conversions
111Explicit numeric conversions
112Binary literals and digit separators
113Hex literals and suffixes
114Raw string literals
115UTF-8 string literals with u8
116Verbatim strings
117Interpolated string formats
118Interpolated string alignment
119Interpolated string handlers
120Escape sequences and \e in C# 13
121Default literals
122Numeric promotion rules
123Generic math with INumber<T>
124Static abstract interface members
125Numeric parsing with INumberBase
126Operator precedence table
127Arithmetic operators and remainder
128Bitwise operators and shifts
129Unsigned right shift >>>
130Compound assignment operators
131Increment and decrement operators
132Conditional operator ?:
133Target-typed conditional expressions
134Null-coalescing assignment ??=
135Null-conditional ?. and ?[]
136Null-forgiving operator !
137Logical pattern operators and, or, not
138Range operator ..
139Index-from-end operator ^
140The is operator
141The as operator
142typeof and nameof operators
143sizeof operator
144default operator
145checked operator
146with expression
147switch expression
148throw expressions
149Lambda discard parameters
150Operator overloading rules
151Overloading checked operators
152Overloading comparison operators
153User-defined conversions implicit and explicit
154true and false operators
155Evaluation order of operands
156if else chains
157switch statement and case guards
158goto case and goto default
159while and do-while loops
160for loops with multiple variables
161foreach and GetEnumerator pattern
162foreach over Span<T>
163foreach deconstruction
164break, continue, and return
165Labeled statements and goto
166lock statement
167lock with System.Threading.Lock in .NET 9
168using statement
169using declaration scope
170fixed statement
171unsafe blocks
172yield return and yield break
173Local functions
174Static local functions
175Local function attributes
176Block-scoped variables and shadowing
177Definite assignment analysis
178Unreachable code warnings
179Await in catch and finally
180Method signatures and overload resolution
181Optional parameters
182Named arguments
183params arrays
184params collections in C# 13
185ref parameters
186out parameters and out var
187in parameters
188ref readonly parameters
189ref returns
190ref locals
191Discards with underscore
192Expression-bodied methods
193Extension method resolution
194Partial methods
195Extended partial methods
196Method groups and conversions
197Caller info attributes
198CallerArgumentExpression
199Recursion and tail calls
200Local functions vs lambdas
201Overload resolution tie-breakers
202Better function member rules
203Method hiding with new
204Generic methods type inference
205Async method signatures
206Iterator methods
207Fields and field initializers
208readonly fields
209const vs static readonly
210Properties with backing fields
211Auto-property initializers
212init-only setters
213required members
214SetsRequiredMembers attribute
215Computed properties
216Indexers
217Multi-parameter indexers
218Primary constructors on classes
219Primary constructors on structs
220Constructor chaining with this
221Static constructors
222Finalizers
223Object initializers
224Collection initializers
225Index initializers
226Target-typed new
227Partial classes
228Nested types
229Static classes
230Sealed classes
231Abstract members
232Access modifiers
233file-scoped types
234internal and protected internal
235private protected
236Object base methods
237Equals and GetHashCode contract
238ToString overrides
239Static members in interfaces
240Partial properties and indexers in C# 13
241Base class constructors
242Virtual and override dispatch
243Method hiding vs overriding
244Covariant return types
245Sealed overrides
246Abstract classes vs interfaces
247Explicit interface implementation
248Default interface methods
249Diamond problem with default interface methods
250Static virtual members
251Interface inheritance
252Liskov substitution in C#
253Protected members design
254Calling base members
255Constructor order of execution
256Virtual calls in constructors hazard
257Object slicing absence
258Polymorphic serialization considerations
259Type testing patterns
260Template method pattern
261Visitor pattern with pattern matching
262Record class declaration
263Positional records
264Record struct
265readonly record struct
266Value equality in records
267Records and GetHashCode
268with expressions and non-destructive mutation
269Record ToString and PrintMembers
270Record inheritance
271Record equality contract with inheritance
272EqualityContract
273Deconstruction of records
274Records with init properties
275Records with validation in constructors
276Records with collections and equality
277Records and serialization
278Records in EF Core
279Records vs classes vs structs
280Sealed ToString in records
281Records as DTOs
282Records as discriminated union approximations
283Records with primary constructor attributes
284Property attribute targets on record parameters
285Struct layout and copying
286Mutable struct pitfalls
287readonly structs
288readonly members
289Struct default constructor
290Struct parameterless constructors
291Boxing and unboxing
292Avoiding boxing
293StructLayout attribute
294FieldOffset and unions
295Fixed-size buffers
296Inline arrays in C# 12
297ref struct rules
298ref fields in ref structs
299scoped keyword
300UnscopedRef attribute
301Span<T> as ref struct
302ref struct interfaces in C# 13
303allows ref struct anti-constraint
304Struct equality performance
305IEquatable<T> on structs
306ref struct disposable pattern
307Declaration pattern
308Type pattern
309Constant pattern
310Relational patterns
311Logical patterns
312Property patterns
313Extended property patterns
314Positional patterns
315var pattern
316Discard pattern
317Parenthesized patterns
318Null patterns
319List patterns
320Slice patterns
321Switch expression exhaustiveness
322Switch expression arms and guards
323Pattern matching on tuples
324Pattern matching with enums
325Pattern matching and nullable flow
326Pattern combinators best practices
327Pattern matching vs polymorphism
328Subsumption and unreachable patterns
329Pattern matching on Span<char>
330String constant patterns
331is not null idiom
332Compiler-generated code for patterns
333Performance of switch lowering
334ValueTuple basics
335Tuple element names
336Tuple equality
337Tuple deconstruction
338Deconstruct methods
339Tuples as return values
340Tuple vs anonymous types
341System.Tuple vs ValueTuple
342Tuple type inference
343Tuple names erasure and TupleElementNames
344Index struct
345Range struct
346Ranges on arrays
347Ranges on strings
348Ranges on List<T>
349Supporting Index and Range in custom types
350Implicit index support
351Slicing with Span
352Anonymous types
353Anonymous type equality
354Named tuples in LINQ
355Enum underlying types
356Enum.Parse and TryParse
357Enum.GetValues<T>
358Enum.GetName and GetNames
359Flags enums
360Flags enum bitwise operations
361Enum.HasFlag cost
362Enum ToString formats
363Enum validation with IsDefined
364Enum extension methods
365Enum switch exhaustiveness
366Enum serialization with System.Text.Json
367Enums vs smart enums
368Enum with Description attribute
369Enum generic constraint
370Enum source generators
371Delegate types
372Multicast delegates
373Delegate invocation lists
374Delegate.Combine and Remove
375Action, Func, and Predicate
376Lambda expressions
377Lambda natural types
378Lambda attributes
379Lambda default parameters
380Static lambdas
381Closures and captured variables
382Closure allocation costs
383Capturing loop variables
384Method group conversion
385Delegate variance
386Events and event accessors
387EventHandler<T> pattern
388Weak event pattern
389Event memory leaks
390Raising events safely
391Custom event accessors with locks
392Async event handlers
393Delegates vs interfaces
394Function pointers delegate*
395Delegate.CreateDelegate
396DynamicInvoke cost
397Delegate equality
398Callbacks and continuations
399Observer pattern with IObservable<T>
400Reactive Extensions basics
401Generic type parameters
402Open and closed generic types
403Generic constraints where T : class
404struct constraint
405new() constraint
406unmanaged constraint
407notnull constraint
408Base class constraints
409Interface constraints
410default constraint
411Multiple constraints
412Covariance with out
413Contravariance with in
414Variance in IEnumerable and Action
415Variant interfaces design
416Generic delegates variance
417Generic static members
418Static abstract members in generics
419Generic math interfaces
420Generics and reflection
421Generics at runtime with CLR specialization
422Generic sharing for reference types
423Generic virtual methods
424Generic type inference limits
425Recursive generics CRTP
426Generic attributes
427Generic collections vs non-generic
428Constraint on enum and delegate
429Generic repository pitfalls
430Phantom types
431Enabling nullable context
432Nullable annotations ? and !
433Nullable flow analysis
434Nullable warnings catalog
435AllowNull and DisallowNull
436MaybeNull and NotNull
437MaybeNullWhen and NotNullWhen
438NotNullIfNotNull
439MemberNotNull and MemberNotNullWhen
440DoesNotReturn and DoesNotReturnIf
441Nullable generics and T?
442Nullable and unconstrained generics
443Nullable in libraries
444Nullable migration strategy
445Nullable with EF Core
446Nullable with JSON deserialization
447Nullable and required members
448Nullable attributes on parameters
449#nullable directives
450Nullable and arrays
451Nullable value types vs reference types
452Nullable pitfalls with default!
453ArgumentNullException.ThrowIfNull
454Null object pattern
455Exception hierarchy
456try catch finally semantics
457Exception filters with when
458Rethrow vs throw ex
459Exception stack traces
460Inner exceptions
461AggregateException
462ExceptionDispatchInfo
463Custom exception design
464Exception serialization
465First-chance exceptions
466Unhandled exceptions
467AppDomain UnhandledException
468Exception cost
469Throw helpers pattern
470Result type alternative
471TryParse pattern
472Exception in finalizers
473Exception in iterators
474Exceptions and async
475Exceptions in constructors
476StackOverflow and OutOfMemory
477Fail-fast with Environment.FailFast
478Guard clauses
479Exception handling in Parallel
480C# 8 features overview
481C# 9 features overview
482C# 10 features overview
483C# 11 features overview
484C# 12 features overview
485C# 13 features overview
486Collection expressions
487Collection expression spread element
488Collection expression target types
489Collection builder attribute
490Alias any type with using
491Primary constructor parameter capture
492Experimental attribute
493Interceptors
494InterceptsLocation attribute
495file-local types
496Newlines in interpolations
497Module initializers
498Top-level programs
499Global usings
500Lambda improvements C# 10
501Constant interpolated strings
502Implicit index access in object initializers
503ref and unsafe in iterators and async in C# 13
504Extension method basics and rules
505Extension methods on interfaces
506Extension methods on generics
507Extension methods on enums
508Extension methods on delegates
509Extension methods on tuples
510Extension methods on ref structs
511Extension methods and null
512Extension method discoverability and namespaces
513Extension methods vs instance methods precedence
514Extension method pitfalls
515Extension GetEnumerator
516Extension Deconstruct
517Extension Add for collection initializers
518Extension GetAwaiter
519Designing extension libraries
520Attribute basics
521AttributeUsage
522Custom attributes
523Attribute parameters
524Attribute targets
525Reading attributes with reflection
526Inherited attributes
527Conditional attribute
528Obsolete attribute
529Flags and Serializable
530InternalsVisibleTo
531ModuleInitializer
532SkipLocalsInit
533MethodImpl options
534Assembly attributes
535DebuggerDisplay
536DebuggerStepThrough
537DebuggerTypeProxy
538StackTraceHidden
539UnconditionalSuppressMessage
540DynamicallyAccessedMembers
541dynamic keyword
542DLR and ExpandoObject
543DynamicObject
544Binder and CallSite
545Unsafe code basics
546Pointers and address-of
547Pointer arithmetic
548stackalloc
549stackalloc in Span
550fixed buffers
551Function pointers
552unmanaged callers only
553Unsafe class helpers
554MemoryMarshal
555Marshal class
556Pinning with GCHandle
557Pinned arrays and fixed
558NativeMemory
559Volatile and Interlocked
560Unmanaged constraint use cases
561Preprocessor directives
562#region and #pragma
563Conditional compilation
564#line directive
565Nullable directives
566#define and symbols
567C# scripting with csi

97sbyte and byte ranges
98short and ushort
99int and uint arithmetic
100long and ulong
101nint and nuint native integers
102Int128 and UInt128
103Half floating point
104float and double IEEE 754
105decimal precision and scaling
106char and UTF-16 code units
107bool and logical operators
108Checked and unchecked contexts
109Integer overflow behavior
110Implicit numeric conversions
111Explicit numeric conversions
112Binary literals and digit separators
113Hex literals and suffixes
114Raw string literals
115UTF-8 string literals with u8
116Verbatim strings
117Interpolated string formats
118Interpolated string alignment
119Interpolated string handlers
120Escape sequences and \e in C# 13
121Default literals
122Numeric promotion rules
123Generic math with INumber<T>
124Static abstract interface members
125Numeric parsing with INumberBase
126Operator precedence table
127Arithmetic operators and remainder
128Bitwise operators and shifts
129Unsigned right shift >>>
130Compound assignment operators
131Increment and decrement operators
132Conditional operator ?:
133Target-typed conditional expressions
134Null-coalescing assignment ??=
135Null-conditional ?. and ?[]
136Null-forgiving operator !
137Logical pattern operators and, or, not
138Range operator ..
139Index-from-end operator ^
140The is operator
141The as operator
142typeof and nameof operators
143sizeof operator
144default operator
145checked operator
146with expression
147switch expression
148throw expressions
149Lambda discard parameters
150Operator overloading rules
151Overloading checked operators
152Overloading comparison operators
153User-defined conversions implicit and explicit
154true and false operators
155Evaluation order of operands
156if else chains
157switch statement and case guards
158goto case and goto default
159while and do-while loops
160for loops with multiple variables
161foreach and GetEnumerator pattern
162foreach over Span<T>
163foreach deconstruction
164break, continue, and return
165Labeled statements and goto
166lock statement
167lock with System.Threading.Lock in .NET 9
168using statement
169using declaration scope
170fixed statement
171unsafe blocks
172yield return and yield break
173Local functions
174Static local functions
175Local function attributes
176Block-scoped variables and shadowing
177Definite assignment analysis
178Unreachable code warnings
179Await in catch and finally
180Method signatures and overload resolution
181Optional parameters
182Named arguments
183params arrays
184params collections in C# 13
185ref parameters
186out parameters and out var
187in parameters
188ref readonly parameters
189ref returns
190ref locals
191Discards with underscore
192Expression-bodied methods
193Extension method resolution
194Partial methods
195Extended partial methods
196Method groups and conversions
197Caller info attributes
198CallerArgumentExpression
199Recursion and tail calls
200Local functions vs lambdas
201Overload resolution tie-breakers
202Better function member rules
203Method hiding with new
204Generic methods type inference
205Async method signatures
206Iterator methods
207Fields and field initializers
208readonly fields
209const vs static readonly
210Properties with backing fields
211Auto-property initializers
212init-only setters
213required members
214SetsRequiredMembers attribute
215Computed properties
216Indexers
217Multi-parameter indexers
218Primary constructors on classes
219Primary constructors on structs
220Constructor chaining with this
221Static constructors
222Finalizers
223Object initializers
224Collection initializers
225Index initializers
226Target-typed new
227Partial classes
228Nested types
229Static classes
230Sealed classes
231Abstract members
232Access modifiers
233file-scoped types
234internal and protected internal
235private protected
236Object base methods
237Equals and GetHashCode contract
238ToString overrides
239Static members in interfaces
240Partial properties and indexers in C# 13
241Base class constructors
242Virtual and override dispatch
243Method hiding vs overriding
244Covariant return types
245Sealed overrides
246Abstract classes vs interfaces
247Explicit interface implementation
248Default interface methods
249Diamond problem with default interface methods
250Static virtual members
251Interface inheritance
252Liskov substitution in C#
253Protected members design
254Calling base members
255Constructor order of execution
256Virtual calls in constructors hazard
257Object slicing absence
258Polymorphic serialization considerations
259Type testing patterns
260Template method pattern
261Visitor pattern with pattern matching
262Record class declaration
263Positional records
264Record struct
265readonly record struct
266Value equality in records
267Records and GetHashCode
268with expressions and non-destructive mutation
269Record ToString and PrintMembers
270Record inheritance
271Record equality contract with inheritance
272EqualityContract
273Deconstruction of records
274Records with init properties
275Records with validation in constructors
276Records with collections and equality
277Records and serialization
278Records in EF Core
279Records vs classes vs structs
280Sealed ToString in records
281Records as DTOs
282Records as discriminated union approximations
283Records with primary constructor attributes
284Property attribute targets on record parameters
285Struct layout and copying
286Mutable struct pitfalls
287readonly structs
288readonly members
289Struct default constructor
290Struct parameterless constructors
291Boxing and unboxing
292Avoiding boxing
293StructLayout attribute
294FieldOffset and unions
295Fixed-size buffers
296Inline arrays in C# 12
297ref struct rules
298ref fields in ref structs
299scoped keyword
300UnscopedRef attribute
301Span<T> as ref struct
302ref struct interfaces in C# 13
303allows ref struct anti-constraint
304Struct equality performance
305IEquatable<T> on structs
306ref struct disposable pattern
307Declaration pattern
308Type pattern
309Constant pattern
310Relational patterns
311Logical patterns
312Property patterns
313Extended property patterns
314Positional patterns
315var pattern
316Discard pattern
317Parenthesized patterns
318Null patterns
319List patterns
320Slice patterns
321Switch expression exhaustiveness
322Switch expression arms and guards
323Pattern matching on tuples
324Pattern matching with enums
325Pattern matching and nullable flow
326Pattern combinators best practices
327Pattern matching vs polymorphism
328Subsumption and unreachable patterns
329Pattern matching on Span<char>
330String constant patterns
331is not null idiom
332Compiler-generated code for patterns
333Performance of switch lowering
334ValueTuple basics
335Tuple element names
336Tuple equality
337Tuple deconstruction
338Deconstruct methods
339Tuples as return values
340Tuple vs anonymous types
341System.Tuple vs ValueTuple
342Tuple type inference
343Tuple names erasure and TupleElementNames
344Index struct
345Range struct
346Ranges on arrays
347Ranges on strings
348Ranges on List<T>
349Supporting Index and Range in custom types
350Implicit index support
351Slicing with Span
352Anonymous types
353Anonymous type equality
354Named tuples in LINQ
355Enum underlying types
356Enum.Parse and TryParse
357Enum.GetValues<T>
358Enum.GetName and GetNames
359Flags enums
360Flags enum bitwise operations
361Enum.HasFlag cost
362Enum ToString formats
363Enum validation with IsDefined
364Enum extension methods
365Enum switch exhaustiveness
366Enum serialization with System.Text.Json
367Enums vs smart enums
368Enum with Description attribute
369Enum generic constraint
370Enum source generators
371Delegate types
372Multicast delegates
373Delegate invocation lists
374Delegate.Combine and Remove
375Action, Func, and Predicate
376Lambda expressions
377Lambda natural types
378Lambda attributes
379Lambda default parameters
380Static lambdas
381Closures and captured variables
382Closure allocation costs
383Capturing loop variables
384Method group conversion
385Delegate variance
386Events and event accessors
387EventHandler<T> pattern
388Weak event pattern
389Event memory leaks
390Raising events safely
391Custom event accessors with locks
392Async event handlers
393Delegates vs interfaces
394Function pointers delegate*
395Delegate.CreateDelegate
396DynamicInvoke cost
397Delegate equality
398Callbacks and continuations
399Observer pattern with IObservable<T>
400Reactive Extensions basics
401Generic type parameters
402Open and closed generic types
403Generic constraints where T : class
404struct constraint
405new() constraint
406unmanaged constraint
407notnull constraint
408Base class constraints
409Interface constraints
410default constraint
411Multiple constraints
412Covariance with out
413Contravariance with in
414Variance in IEnumerable and Action
415Variant interfaces design
416Generic delegates variance
417Generic static members
418Static abstract members in generics
419Generic math interfaces
420Generics and reflection
421Generics at runtime with CLR specialization
422Generic sharing for reference types
423Generic virtual methods
424Generic type inference limits
425Recursive generics CRTP
426Generic attributes
427Generic collections vs non-generic
428Constraint on enum and delegate
429Generic repository pitfalls
430Phantom types
431Enabling nullable context
432Nullable annotations ? and !
433Nullable flow analysis
434Nullable warnings catalog
435AllowNull and DisallowNull
436MaybeNull and NotNull
437MaybeNullWhen and NotNullWhen
438NotNullIfNotNull
439MemberNotNull and MemberNotNullWhen
440DoesNotReturn and DoesNotReturnIf
441Nullable generics and T?
442Nullable and unconstrained generics
443Nullable in libraries
444Nullable migration strategy
445Nullable with EF Core
446Nullable with JSON deserialization
447Nullable and required members
448Nullable attributes on parameters
449#nullable directives
450Nullable and arrays
451Nullable value types vs reference types
452Nullable pitfalls with default!
453ArgumentNullException.ThrowIfNull
454Null object pattern
455Exception hierarchy
456try catch finally semantics
457Exception filters with when
458Rethrow vs throw ex
459Exception stack traces
460Inner exceptions
461AggregateException
462ExceptionDispatchInfo
463Custom exception design
464Exception serialization
465First-chance exceptions
466Unhandled exceptions
467AppDomain UnhandledException
468Exception cost
469Throw helpers pattern
470Result type alternative
471TryParse pattern
472Exception in finalizers
473Exception in iterators
474Exceptions and async
475Exceptions in constructors
476StackOverflow and OutOfMemory
477Fail-fast with Environment.FailFast
478Guard clauses
479Exception handling in Parallel
480C# 8 features overview
481C# 9 features overview
482C# 10 features overview
483C# 11 features overview
484C# 12 features overview
485C# 13 features overview
486Collection expressions
487Collection expression spread element
488Collection expression target types
489Collection builder attribute
490Alias any type with using
491Primary constructor parameter capture
492Experimental attribute
493Interceptors
494InterceptsLocation attribute
495file-local types
496Newlines in interpolations
497Module initializers
498Top-level programs
499Global usings
500Lambda improvements C# 10
501Constant interpolated strings
502Implicit index access in object initializers
503ref and unsafe in iterators and async in C# 13
504Extension method basics and rules
505Extension methods on interfaces
506Extension methods on generics
507Extension methods on enums
508Extension methods on delegates
509Extension methods on tuples
510Extension methods on ref structs
511Extension methods and null
512Extension method discoverability and namespaces
513Extension methods vs instance methods precedence
514Extension method pitfalls
515Extension GetEnumerator
516Extension Deconstruct
517Extension Add for collection initializers
518Extension GetAwaiter
519Designing extension libraries
520Attribute basics
521AttributeUsage
522Custom attributes
523Attribute parameters
524Attribute targets
525Reading attributes with reflection
526Inherited attributes
527Conditional attribute
528Obsolete attribute
529Flags and Serializable
530InternalsVisibleTo
531ModuleInitializer
532SkipLocalsInit
533MethodImpl options
534Assembly attributes
535DebuggerDisplay
536DebuggerStepThrough
537DebuggerTypeProxy
538StackTraceHidden
539UnconditionalSuppressMessage
540DynamicallyAccessedMembers
541dynamic keyword
542DLR and ExpandoObject
543DynamicObject
544Binder and CallSite
545Unsafe code basics
546Pointers and address-of
547Pointer arithmetic
548stackalloc
549stackalloc in Span
550fixed buffers
551Function pointers
552unmanaged callers only
553Unsafe class helpers
554MemoryMarshal
555Marshal class
556Pinning with GCHandle
557Pinned arrays and fixed
558NativeMemory
559Volatile and Interlocked
560Unmanaged constraint use cases
561Preprocessor directives
562#region and #pragma
563Conditional compilation
564#line directive
565Nullable directives
566#define and symbols
567C# scripting with csi

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AllowNull and DisallowNull

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