Records - C# Reference (2023)

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  • 17 minutes to read

Starting with C# 9, use therecordKeyword to define areference typethat provides built-in functionality for encapsulating data. C# 10 allowsrecord classSyntax as a synonym to clarify a reference type andrecord structureset avalue typewith similar functionality. You can create record types with immutable properties using positional parameters or standard property syntax.

The following two examples demonstraterecord(orrecord class) Types of reference:

public record Person(string FirstName, string LastName);
public record Person{ public required string Name { get; inside; } string required public lastname { get; inside; }};

The following two examples demonstraterecord structureValue types:

public record readonly struct Point(double X, double Y, double Z);
public record struct Point{ public double X { get; inside; } audience double Y { get; inside; } public double Z { get; inside; }}

You can also create records with editable properties and fields:

public record Person{ public required string Name { get; Phrase; } string required public lastname { get; Phrase; }};

Record structures can also be mutable, either positional record structures or record structures without positional parameters:

public record structure DataMeasurement(DateTime TakenAt, Double Measurement);
public record struct Point{ public double X { get; Phrase; } audience double Y { get; Phrase; } public double Z { get; Phrase; }}

Although datasets can be mutable, they are primarily intended to support immutable data models. The record type provides the following features:

  • Concise syntax for creating a reference type with immutable properties
  • Useful built-in behavior for a data-centric reference type:
    • equality of values
    • Short syntax for nondestructive mutation
    • Integrated display formatting
  • Support for inheritance hierarchies

The previous examples show some differences between records that are reference types and records that are value types:

  • Arecordor onerecord classdeclares a reference type. OClassroomThe keyword is optional, but it can provide clarity for readers. Arecord structuredeclares a value type.
  • The position properties areimmutableon arecord classit is aread-only record structure. They aremutableon arecord structure.

The rest of this article covers both.record classErecord structuretypes. Differences are detailed in each section. You must choose between onerecord classit is arecord structuresimilar to the decision between aClassroomit is aStructure. the termrecordused to describe behavior that applies to all record types. Anyrecord structureorrecord classused to describe the unique behavior of struct or class types. Orecordtype was introduced in C# 9;record structuretypes were introduced in C# 10.

Positional syntax for property definition

You can use positional parameters to declare properties of a record and initialize property values ​​when creating an instance:

public record Person(string FirstName, string LastName); public static void Main(){ Person person = new("Nancy", "Davolio"); Console WriteLine(Pessoa); // Output: Person { First Name = Nancy, Last Name = Davolio } }

If you use positional syntax for the property definition, the compiler will output the following:

  • An automatically implemented public property for each positional parameter provided in the record declaration.
    • Forrecordtypes andread-only record structuretype: onenur initProperty.
    • Forrecord structureTypes: A read/write property.
  • A primary constructor whose parameters match the positional parameters in the record declaration.
  • For record structure types, a parameterless constructor that sets each field to its default value.
  • Adeconstructmethod with aoutside ofParameters for each positional parameter specified in the record declaration. The method deconstructs the defined properties using positional syntax; it ignores properties defined using standard property syntax.

You might want to add attributes to each of these elements that the compiler creates from the record definition. You can add aMetato any attribute applied to location record properties. The following example applies toSystem.Text.Json.Serialization.JsonPropertyNameAttributeto each property ofPersonrecord. OProperty:target indicates that the attribute is applied to the property generated by the compiler. Other values ​​areCampo:to apply the attribute to the field, andParameter:to apply the attribute to the parameter.

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/// <summary>/// Person Record Type /// </summary>/// <param name="FirstName">First Name</param>/// <param name="LastName">Last Name< /param>/ // <notes>/// The person type is a location record that contains /// the first and last name properties. These /// properties are mapped to JSON elements "firstName" and "lastName" if /// they have been serialized or deserialized./// </remarks>Public record Person([property: JsonPropertyName("firstName")] string FirstName , [ Property: JsonPropertyName("lastName")]string LastName);

The previous example also shows how to create XML documentation comments for the dataset. You can add those<param>tag to add documentation for the primary parameters of the constructor.

If the generated self-implemented property definition is not what you want, you can define your own property with the same name. For example, you might want to change accessibility or mutability, or provide an implementation forto receiveorPhraseaccessor. If you declare the property in your source, you must initialize it from the record's positional parameter. If your property is an automatically implemented property, you must initialize it. If you add a background field to your source, you must initialize the background field. The generated destructor uses your property definition. For example, the following example declares theFirst nameElast name, last nameProperties of a position recordpublic, but restricts themI WENTposition parameter tootrainee. You can use this syntax for records and record structure types.

public record Person(string FirstName, string LastName, string Id){ internal string Id { get; inside; } = ID;}public static void Main(){ Person person = new("Nancy", "Davolio", "12345"); Console.WriteLine(person.Name); //Output: Nancy}

A record type need not declare positional properties. You can declare a record without positional properties, and you can declare other fields and properties, as in the following example:

registro público Pessoa(string FirstName, string LastName){ public string[] PhoneNumbers { get; dentro; } = Array.Empty<string>();};

If you define properties using standard property syntax but omit the access modifier, the properties are impliedPrivate.


Aposition recordit is apositional read-only record structureDeclare initialization-only properties. APosition record structuredeclare read/write properties. You can override any of these defaults as shown in the previous section.

Immutability can be useful when you need a data-centric type that is thread safe or when you depend on a hash code in a hash table to stay the same. However, immutability is not appropriate for all data scenarios.Entity Framework-Kernfor example, it does not support updating with immutable entity types.

Initialization-only properties, regardless of whether they were created from positional parameters (record class, Eread-only record structure) or by specificationinsideaccessors, hasshallow immutability. After initialization, you cannot change the value of value type properties or the reference of reference type properties. However, data referenced by a reference type property can be modified. The following example shows that the contents of an immutable property of the reference type (in this case, an array) is mutable:

öffentlicher Datensatz Person(string FirstName, string LastName, string[] PhoneNumbers);public static void Main(){ Person person = new("Nancy", "Davolio", new string[1] { "555-1234" }); Console.WriteLine(pessoa.PhoneNumbers[0]); // Número de telefone: 555-1234 person.PhoneNumbers[0] = "555-6789"; Console.WriteLine(pessoa.PhoneNumbers[0]); // Ausgabe: 555-6789}

The unique functions of record types are implemented through methods synthesized by the compiler, and none of these methods break immutability by changing the state of the object. Unless otherwise noted, synthesized procedures are generated torecord,record structure, Eread-only record structureExplanations.

equality of values

Unless you override or override equality methods, the type you declare determines how equality is defined:

  • ForClassroomTypes are two objects the same if they refer to the same object in memory.
  • ForStructureTypes Two objects are equal if they are of the same type and store the same values.
  • Forrecordspecies, includingrecord structureEread-only record structure, two objects are equal if they are of the same type and store the same values.

The definition of equality for arecord structureis the same as for aStructure. The difference is that for aStructure, the implementation is thereValueType.Equals(Object)and depends on reflection. For datasets, the implementation is synthesized by the compiler and uses the declared data members.

Reference equality is required for some data models. For example,Entity Framework-Kernrelies on equality of reference to ensure that only one instance of an entity type is used for a conceptually unique entity. Because of this, records and record structures are not appropriate for use as entity types in Entity Framework Core.

The following example illustrates the value equality of record types:

registro público Person(string FirstName, string LastName, string[] PhoneNumbers); public static void Main(){ var phoneNumbers = new string[2]; Pessoa pessoa1 = new("Nancy", "Davolio", phoneNumbers); Pessoa pessoa2 = new("Nancy", "Davolio", phoneNumbers); Console.WriteLine(pessoa1 == pessoa2); // Output: True person1.PhoneNumbers[0] = "555-1234"; Console.WriteLine(pessoa1 == pessoa2); // output: True Console.WriteLine(ReferenceEquals(person1, person2)); // saída: falso}

To implement value equality, the compiler synthesizes several methods, including:

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  • A rewrite ofObject.Equals(Objekt). It is an error if the override is explicitly declared.

    This method serves as the basis forObject.Equals(object, object)static method if both parameters are not null.

  • Avirtual, orsealed,Same (R? other)WoRis the record type. Implemented this methodIEquatable<T>. This method can be declared explicitly.

  • If the record type is derived from a base record typeBase,Same (base? other). It is an error if the override is explicitly declared. If you provide your own implementation ofSame (R? other), provide an implementation ofGetHashCodeAlso.

  • A rewrite ofObject.GetHashCode(). This method can be declared explicitly.

  • Operator Overrides==E!=. It is an error if operators are explicitly declared.

  • If the record type is derived from a base record type,protected substitution Type EqualityContract { get; };. This property can be declared explicitly. For more information, seeEquality in inheritance hierarchies.

If a record type has a method that matches the signature of a synthesized method that can be declared explicitly, the compiler will not synthesize that method.

nondestructive mutation

If you need to copy an instance with some modifications, you cancomto achieve the expressionnondestructive mutation. AcomExpression creates a new record instance that is a copy of an existing record instance by modifying certain properties and fields. you useobject initializerSyntax to specify the values ​​to be changed, according to the following example:

registro público Pessoa(string FirstName, string LastName){ public string[] PhoneNumbers { get; dentro; }}public static void Main(){ Person person1 = new("Nancy", "Davolio") {PhoneNumbers = new string[1] }; Console WriteLine (pessoa1); // Output: Person { FirstName = Nancy, LastName = Davolio, PhoneNumbers = System.String[] } Person person2 = person1 with { FirstName = "John" }; Console WriteLine (pessoa2); // Output: Person { FirstName = John, LastName = Davolio, PhoneNumbers = System.String[] } Console.WriteLine(person1 == person2); // Output: False person2 = person1 with { PhoneNumbers = new string[1] }; Console WriteLine (pessoa2); // Output: Person { FirstName = Nancy, LastName = Davolio, PhoneNumbers = System.String[] } Console.WriteLine(person1 == person2); // Saída: Pessoa2 errada = pessoa1 com { }; Console.WriteLine(pessoa1 == pessoa2); // saída: verdadeiro}

OcomThe expression can specify positional or constructed properties using standard property syntax. Non-positional properties must have ainsideorPhraseAccessor to change in onecomExpression.

The result of acomexpression is ashallow copy, which means that for a reference property, only the reference to an instance is copied. Both the original record and the copy end with a reference to the same instance.

To implement this function, for examplerecord classtypes, the compiler synthesizes a clone method and a copy constructor. The virtual clone method returns a new record initialized by the copy constructor. If you use acom-expression, the compiler creates code that calls the clone method and then sets the properties specified in thecomExpression.

If you need different copy behavior, you can write your own copy constructor in arecord class. If you do, the compiler will not synthesize any. make your builderPrivateif the record issealed, otherwise doprotected. The compiler does not synthesize a copy constructor forrecord structuretypes. You can write one, but the compiler doesn't generate calls to itcomexpressions. the values ​​ofrecord structureare copied in the order.

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You cannot override the clone method and you cannot create a member by nameCloneon each record type. The actual name of the clone method is generated by the compiler.

Integrated display formatting

Record types have a generated compilerto sequencemethod that displays the names and values ​​of properties and public fields. Oto sequenceThe method returns a string in the following format:

<record type name> { <property name> = <value>, <property name> = <value>, ...}

The string that is produced for<Wert>is the string returned byto sequence()for the type of property. In the example belowchildren's namesit is aSystem.Array, Woto sequenceReturnsSystem.String[]:

Pessoa { FirstName = Nancy, LastName = Davolio, ChildNames = System.String[] }

To implement this function inrecord classtypes, the compiler synthesizes a virtualPrintMembersmethod and ato sequenceto replace. Inrecord structureGuys, this member isPrivate.Oto sequenceReplace created aStringBuilderObject with the name of the type followed by an opening square bracket. he callsPrintMembersto add property names and values, and then add the closing square bracket. The following example shows code similar to the content of the synthesized replacement:

substituição pública string ToString(){ StringBuilder stringBuilder = new StringBuilder(); stringBuilder.Append("Lehrer"); // Name eingeben stringBuilder.Append(" { "); if (PrintMembers(stringBuilder)) { stringBuilder.Append(" "); } stringBuilder.Append("}"); return stringBuilder.ToString();}

You can provide your own implementation ofPrintMembersor theto sequenceto replace. Examples can be found inFormatting PrintMembers in Derived Datasetssection later in this article. In C# 10 and later, your implementation ofto sequencecan contain thesealedModifier that prevents the compiler from synthesizing ato sequenceImplementation for all derived datasets. You can do this to create a consistent representation of strings in a hierarchy ofrecordtypes. (The derived records still have aPrintMembersMethod generated for all derived properties.)


This section only applies torecord classThe type.

A record can inherit from another record. However, a record cannot inherit from a class, and a class cannot inherit from a record.

Positional parameters in derived record types

The derived record declares positional parameters for all parameters in the base record's primary constructor. The base record declares and initializes these properties. The derived dataset does not hide them, but just creates and initializes properties for parameters that are not declared in its base dataset.

The following example illustrates inheritance using positional property syntax:

abstract public record Person(string FirstName, string LastName);public record Teacher(string FirstName, string LastName, int Grade): Person(FirstName, LastName);public static void Main(){ Person Teacher = new Teacher("Nancy", "Davólio", 3); Console.WriteLine(professor); // Output: Teacher { First Name = Nancy, Last Name = Davolio, Class = 3 }}

Equality in inheritance hierarchies

This section applies torecord classguys, but norecord structuretypes. For two registry variables to be equal, the runtime type must be the same. The types of the container variables can be different. Inherited equality comparison is illustrated in the following code example:

abstract public record Person(string FirstName, string LastName); public record Teacher(string FirstName, string LastName, int Grade): Person(FirstName, LastName); public record Student(string FirstName, string LastName, int Grade): Person(FirstName , LastName);public static void Main(){ Person Teacher = new Teacher("Nancy", "Davolio", 3); Person student = new Student("Nancy", "Davolio", 3); Console.WriteLine(teacher == student); // Output: False Student student2 = new Student("Nancy", "Davolio", 3); Console.WriteLine(Student2 == Student); // output: true}

In the example, all variables are declared asPerson, even if the instance is a type derived from bothStudentorLehrer. Instances have the same properties and the same property values. Butstudent == teacherReturnsINCORRECTalthough both arePerson-Type variables andstudent == student2ReturnsTRUEalthough one is onePersonvariable and one is oneStudentVariable. The equality test depends on the runtime type of the actual object, not the declared type of the variable.

To implement this behavior, the compiler synthesizes aequality contractProperty returning aTypeObject corresponding to the record type. Oequality contractallows equality methods to compare the type of objects at runtime when checking equality. If the base type of a record isObject, this property isvirtual. If the base type is another record type, this property will be an override. If the record type issealed, this property is effectivesealedbecause the guy issealed.

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When comparing two instances of a derived type, the synthesized equality methods compare all properties of the base type and the derived type for equality. the synthesizedGetHashCodemethod uses theGetHashCodemethod of all properties and fields declared in the base type and derived record type.

comExpressions in Derived Datasets

The result of acomexpression has the same runtime type as the expression's operand. All runtime type properties are copied, but you can only set compile-time type properties, as the following example shows:

conjunto de dados público Point(int X, int Y) { public int Zbase { get; Frase; }}; conjunto de dados público NamedPoint(string Name, int X, int Y) : Point(X, Y){ public int Zderived { get; Frase; }}; public static void Main() { Point p1 = new NamedPoint( "A", 1, 2) { Zbase = 3, Zderived = 4 }; Ponto p2 = p1 com { X = 5, Y = 6, Zbase = 7 }; // Não é possível definir Name ou Zderived Console.WriteLine(p2 is NamedPoint); // Output: True Console.WriteLine(p2); // Output: NamedPoint { X = 5, Y = 6, Zbase = 7, Name = A, Zderived = 4 } Ponto p3 = (NamedPoint)p1 with { Name = "B", X = 5, Y = 6, Zbase = 7, Zderivado = 8 }; Console.WriteLine(p3); // Output: NamedPoint { X = 5, Y = 6, Zbase = 7, Name = B, Zderived = 8 }}

PrintMembersFormatting in Derived Datasets

the synthesizedPrintMembersThe method of a derived record type calls the base implementation. The result is that all properties and public fields of derived and base types are included in theto sequenceoutput as shown in the following example:

abstract public record Person(string FirstName, string LastName); registro público Teacher(string FirstName, string LastName, int Grade): Person(FirstName, LastName); registro público Student(string FirstName, string LastName, int Grade): Person(FirstName , Sobrenome);public static void Main(){ Pessoa Professor = new Professor("Nancy", "Davolio", 3); Console.WriteLine(professor); // Output: Teacher { First Name = Nancy, Last Name = Davolio, Class = 3 }}

You can provide your own implementation ofPrintMembersMethod. In this case, use the following signature:

  • ForsealedRegistration originating fromObject(does not declare a base record):private bool PrintMembers (Construtor StringBuilder);
  • ForsealedRecord derived from another record (note that the delimiter type issealed, then the method is effectivesealed):override protected bool PrintMembers (StringBuilder constructor);
  • For a record that is notsealedand derives from the object:bool virtual protegido PrintMembers(construtor StringBuilder);
  • For a record that is notsealedand comes from another dataset:protected override bool PrintMembers(StringBuilder constructor);

Here is a code example replacing the synthesizedPrintMembersMethods, one for a record type derived from Object and one for a record type derived from another record:

registro abstrato público Pessoa(string FirstName, string LastName, string[] PhoneNumbers){ protected virtual bool PrintMembers(StringBuilder stringBuilder) { stringBuilder.Append($"FirstName = {FirstName}, LastName = {LastName}, "); stringBuilder.Append($"PhoneNumber1 = {PhoneNumbers[0]}, PhoneNumber2 = {PhoneNumbers[1]}"); gib true zurück; }}Public record Teacher(string FirstName, string LastName, string[] PhoneNumbers, int Grade): Person(FirstName, LastName, PhoneNumbers){ protected override bool PrintMembers(StringBuilder stringBuilder) { if (base.PrintMembers(stringBuilder)) { stringBuilder .Anexar(", "); }; stringBuilder.Append($"Nota = {Nota}"); gib true zurück; }};public static void Main(){ Person Teacher = new Teacher("Nancy", "Davolio", new string[2] { "555-1234", "555-6789" }, 3); Console.WriteLine (Lehrer); // Ausgabe: Teacher { FirstName = Nancy, LastName = Davolio, PhoneNumber1 = 555-1234, PhoneNumber2 = 555-6789, Grade = 3 }}


In C# 10 and later, the compiler synthesizesPrintMembersin derived records, even if a base record sealed itto sequenceMethod. You can also create your own implementation ofPrintMembers.

Destructor behavior on derived datasets

Odeconstructmethod of a derived record returns the values ​​of all positional properties of the compile-time type. If the variable type is a base record, only the base record properties are deconstructed unless the object is converted to the derived type. The following example shows calling a destructor on a derived record.

abstract public record Person(string FirstName, string LastName); registro público Teacher(string FirstName, string LastName, int Grade): Person(FirstName, LastName); registro público Student(string FirstName, string LastName, int Grade): Person(FirstName , Sobrenome);public static void Main(){ Pessoa Professor = new Professor("Nancy", "Davolio", 3); var (nome, sobrenome) = professor; // Não desconstrói a nota Console.WriteLine($"{firstName}, {lastName}");// Output: Nancy, Davolio var (fName, lName, grade) = (Teacher)teacher; Console.WriteLine($"{fName}, {lName}, {grau}");// Output: Nancy, Davolio, 3}

General Restrictions

There are no generic constraints that require a type to be a record. The records meet the requirementsClassroomorStructureObligation. To define a restriction on a specific hierarchy of record types, define the restriction on the base record as you would for a base class. For more information, seeRestrictions on type parameters.

C# language specification

For more information, seeKlassenSection ofC# language specification.

For more information about features introduced in C# 9 and later, see the following Feature Suggestion Notes:

  • records
  • Init-only SetterName
  • Income Covariance

See too

  • C# Reference
  • Design guidelines - choose between class and structure
  • Project Guidelines - Structural Project
  • The C# Type System
  • with expression


Is record reference type C#? ›

C# 9 introduces records, a new reference type that you can create instead of classes or structs. C# 10 adds record structs so that you can define records as value types. Records are distinct from classes in that record types use value-based equality.

Can records inherit C#? ›

A record can inherit from another record. However, a record can't inherit from a class, and a class can't inherit from a record.

Are records immutable C#? ›

In C# 9, a record type is a lightweight, immutable data type (or lightweight class) with primarily read-only properties. A record type is thread-safe, and because it is immutable, you cannot change it after it is created.

What are records vs class? ›

The main difference between class and record type in C# is that a record has the main purpose of storing data, while class define responsibility. Records are immutable, while classes are not.

What is record with reference? ›

A reference record is a record that is used in multiple other records so that any parameters (Host, Port, User, Password, Certificate, Passphrase or custom fields) can be shared.

What data type is a reference? ›

In other words, a variable of class type is called reference data type. It contains the address (or reference) of dynamically created objects. For example, if Demo is a class and we have created its object d, then the variable d is known as a reference type. It refers to objects.

Do private variables get inherited C#? ›

Even though a derived class inherits the private members of a base class, it cannot access those members. However, all those private members are still present in the derived class and can do the same work they would do in the base class itself.

Are fields inherited in C#? ›

In C#, it is possible to inherit fields and methods from one class to another. We group the "inheritance concept" into two categories: Derived Class (child) - the class that inherits from another class.

Can a class be static in C#? ›

Static in c# is used to create a static class, struct, or member. A static class can only contain static data members, including static methods, static constructors, and static properties. In C#, a static class is a class that cannot be instantiated.

Are records called tuples? ›

Records are similar to tuples, in that they group together various data elements. A record has fields, and these are named. While tuples are an ordered collection of data values, a tuple is an unordered collection of labeled data values.

Are records serializable? ›

Records are serialized differently than ordinary serializable or externalizable objects. The serialized form of a record object is a sequence of values derived from the record components. The stream format of a record object is the same as that of an ordinary object in the stream.

Do records degrade with use? ›

The more you use your records, the more they will deteriorate. Like anything physical, the friction between two surfaces will gradually add wear and tear (in this case the contact of the stylus on the record's grooves). On top of this, you'll also have the handling of the records and how often you move them around.

What are the 4 categories of records? ›

Types of Records
  • I. Administrative Records. Records which pertain to the origin, development, activities, and accomplishments of the agency. ...
  • II. Legal Records. ...
  • III. Fiscal Records. ...
  • IV. Historical Records. ...
  • V. Research Records. ...
  • VI. Electronic Records.

What are the two types of records? ›

Records can be divided into two categories: 1) Official, and 2) Transitory/Convenience. "Official records" are: records having the legally recognized and judicially enforceable quality of establishing some fact, policy, or institutional position or decision.

What are the three main types of records? ›

The following sections will provide general guidance on the disposition of 4 types of records:
  • Temporary records.
  • Permanent records.
  • Unscheduled records.
  • Records on legal hold.
Dec 15, 2021

How do you cite records? ›

The information should include the publication number, roll or fiche number, and, if available, frame number(s). After the initial citation, subsequent citations to the same publication may be abbreviated by citing the publication number, roll, and frame or fiche numbers.

Why is it necessary to cross reference some records? ›

As a general rule, you should cross-reference a record if doing so will save you time when you need to retrieve the item later. Too many cross-references, however, will make finding files more difficult. Follow any company guide- lines that are provided to help you know when to make a cross-reference.

Does reference mean copy? ›

The copies are basically new items, with new IDs but with identical content. These items are completely separate from the original items, meaning that any changes in the original items will not be carried out in the new items. On the other hand, a reference is simply a link to the original exercise.

What are reference types C#? ›

C# Reference Types

In C#, classes and interfaces are reference types. Variables of reference types store references to their data (objects) in memory, and they do not contain the data itself. An object of type Object , string , or dynamic is also a reference type.

Is C# string a reference type? ›

A String is a reference type even though it has most of the characteristics of a value type such as being immutable and having == overloaded to compare the text rather than making sure they reference the same object.

What is reference and value type in C#? ›

Value types and reference types are the two main categories of C# types. A variable of a value type contains an instance of the type. This differs from a variable of a reference type, which contains a reference to an instance of the type.

Which classes Cannot be inherited in C#? ›

A sealed class, in C#, is a class that cannot be inherited by any class but can be instantiated.

What is difference between internal and private in C#? ›

protected internal: The type or member can be accessed by any code in the assembly in which it's declared, or from within a derived class in another assembly. private protected: The type or member can be accessed by types derived from the class that are declared within its containing assembly.

What is protected vs private C#? ›

private - can only be accessed from with in the class it is a part of. protected - can only be accessed from with in the class or any object that inherits off of the class.

What is difference between field and property in C#? ›

In C#, a field is a variable (that can be of any type) that is defined inside a class. It can be used to define the characteristics of an object or a class. On the other hand, a property is a member of the class that provides an abstraction to set (write) and get (read) the value of a private field.

Can we inherit both class and interface in C#? ›

A class can inherit from one superclass and can implement as many interfaces as it wishes.

What are interfaces in C#? ›

An interface defines a contract. Any class or struct that implements that contract must provide an implementation of the members defined in the interface. An interface may define a default implementation for members. It may also define static members in order to provide a single implementation for common functionality.

Is a static class a singleton? ›

The difference between the Singleton and Static is Singleton Class can have value when Class object instantiated between server and client, such a way if three client want to have a shared data between them Singleton can be used. Static are always just shared and have no instance but multiple references.

What is difference between static and singleton class in C#? ›

While you can clone an instance of a singleton class, the same is not possible in a static class. You can have the Dispose method in a singleton class but not in a static class. You cannot instantiate a static class, so it cannot be used wherever the “this” reference is required (an indexer, a method parameter).

What is singleton class in C#? ›

Singleton is a creational design pattern, which ensures that only one object of its kind exists and provides a single point of access to it for any other code. Singleton has almost the same pros and cons as global variables. Although they're super-handy, they break the modularity of your code.

Are rows also known as records? ›

A row in a database is also termed as record or tuple. Tuples contain all the data related to a particular single record in the database.

What is a tuple a row or record? ›

A tuple is a single row in a database that contains a single record for such a relation. A row or record is another name for a single item in a table, which is what a triple is. In math, they simply consist of an ordered list of elements and typically represent a set of connected data.

Is tuple a column or row? ›

In the context of a relational database, a row—also called a tuple—represents a single, implicitly structured data item in a table. In simple terms, a database table can be thought of as consisting of rows and columns.

Do static fields get serialized? ›

In Java, serialization is a concept using which we can write the state of an object into a byte stream so that we can transfer it over the network (using technologies like JPA and RMI). But, static variables belong to class therefore, you cannot serialize static variables in Java.

Do records have setters? ›

Final and Immutable

Observe that records do not have the classic getters and setters and therefore, it is impossible to modify their values once they are assigned.

What should never be serialized? ›

Examples of sensitive data that should never be serialized include cryptographic keys, digital certificates, and classes that may hold references to sensitive data at the time of serialization. This rule is meant to prevent the unintentional serialization of sensitive information.

What should you not do with records? ›

  1. Touching the record surface. Let's start with the basics: touching the record surface is a big no-no. ...
  2. Stacking your records. ...
  3. Carelessly returning the record to its sleeve. ...
  4. Bad cleaning practice. ...
  5. Cueing up records with your hand. ...
  6. Not waiting for the record platter to STOP. ...
  7. Not Changing Your Stylus Regularly.
Apr 26, 2022

How do you avoid damaging records? ›

Store Your Records in Dry Place

Always keep the records in a dry and cool place to avoid direct sunlight and heat. Your storage room should be comfortable with a room temperature of 65-75 degrees. Humidity can also harm your record, so keep the humidity below 50% to ensure the records spin for years.

Are records easy to damage? ›

Records are fragile by design, making it easy to scratch them if you remove the record while the platter is spinning. Be patient and let the record complete the revolution before you remove it, which will prevent scratching of the vinyl.

What are 7 records called? ›

7-inch records are often referred to as 45s due to their play speed being 45 RPM. These records are noticeably smaller than their LP counterparts, and they spin significantly faster. The higher RPM gives 45s superior sound quality, but it also means that only a few minutes of recorded sound can be stored on each side.

What are record data type? ›

A record type is a composite data type that consists of one or more identifiers and their corresponding data types. You can create user-defined record types by using the TYPE IS RECORD statement within a package or by using the CREATE TYPE (Object) statement. Dot notation is used to reference fields in a record.

How do you classify the records? ›

Typically, records are classified according to a predetermined set of rules or criteria, such as their business value, legal requirements, or retention periods. This allows organizations to easily and accurately identify, retrieve, and manage the records they need in a timely manner.

What is the purpose of records? ›

Their purpose is to provide reliable evidence of, and information about, 'who, what, when, and why' something happened. In some cases, the requirement to keep certain records is clearly defined by law, regulation, or professional practice.

What are single records called? ›

A "single album" refers to a physical release (like CD, LP or some other media) collecting one or more singles, while a "single" is only a song itself, typically a digital stream or download.

What are the values of records? ›

Besides administrative and fiscal value, records may also have legal value.
Records have value to an agency because:
  • They are the basic administrative tool by which the agency conducts its business.
  • They document the agency's organization, functions, policies, decisions, procedures, and essential transactions.
Jun 6, 2019

What are examples for records? ›

Records include books, letters, documents, printouts, photographs, film, tape, microfiche, microfilm, photostats, sound recordings, maps, drawings, and a voice, data, or video representation held in computer memory.” Records are retained for administrative, financial, historical, or legal reasons.

What are five 5 kinds of records that must be kept? ›

The most common business records include:
  • Employee names, addresses, and contact information.
  • Employee timesheets.
  • Employee pay stubs.
  • All tax forms submitted to the IRS.
  • Bank statements.
  • Insurance documents.
  • Contracts, including loans and mortgages.
  • Purchase receipts.
May 18, 2022

What are 4 characteristics of records? ›

Based on this study the essential characteristics of records were identified as context, form, organization, structure and version/copy.

Which is a reference type in C#? ›

There are two kinds of types in C#: reference types and value types. Variables of reference types store references to their data (objects), while variables of value types directly contain their data.

Which is a reference data type in C#? ›

The built-in reference types supported by C# include: object, string, and dynamic.

Is C# list reference type? ›

List is a reference type since it's a class.

Is record a data type? ›

A record type is a composite data type that consists of one or more identifiers and their corresponding data types. You can create user-defined record types by using the TYPE IS RECORD statement within a package or by using the CREATE TYPE (Object) statement. Dot notation is used to reference fields in a record.

How to use reference variable in C#? ›

How to assign a reference to a variable in C# To assign reference to a variable, use the ref keyword. A reference parameter is a reference to a memory location of a variable. When you pass parameters by reference, unlike value parameters, a new storage location is not created for these parameters.

Does C# have pointers or references? ›

To store an address in memory of a variable. A pointer is a variable itself and has a value whereas a reference only has a variable that it is referencing.

Why class is a reference data type? ›

Because using a class name as a type declares a reference to an object, such types are called reference types. Java also allows the use of an interface name to specify a reference type. In addition, array types in Java are reference types because Java treats arrays as objects.

Is data table reference type? ›

They are both reference types. You can look up the information on MSDN - if they are classes, they are reference types, if structs, value types. See DataTable and DataSet . As you can see, they are both declared as classes.

What is the difference between reference type and pointer type in C#? ›

A major difference between a reference and a pointer is that a pointer is a collection of bits whose content only matters when it is actively being used as a pointer, while a reference encapsulates not only a set of bits, but also some metadata which keeps the underlying framework informed of its existence.

Are C# variables references? ›

The ref keyword indicates that a variable is a reference, or an alias for another object. It's used in five different contexts: In a method signature and in a method call, to pass an argument to a method by reference. For more information, see Passing an argument by reference.

What are the 3 main types of records? ›

The following sections will provide general guidance on the disposition of 4 types of records:
  • Temporary records.
  • Permanent records.
  • Unscheduled records.
  • Records on legal hold.
Dec 15, 2021

What is an example of record? ›

Examples include documents, books, paper, electronic records, photographs, videos, sound recordings, databases, and other data compilations that are used for multiple purposes, or other material, regardless of physical form or characteristics.

What's a record type? ›

Record types let you offer different business processes, picklist values, and Page layouts to different users. For example, one of the most common use cases of record Types would be to create two different sales processes on the Opportunity object – each with different sales stages and Page layouts.


1. C# Language Highlights: Records
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3. C# 9 - Record Types Introduction & Deep-Dive
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4. C# Data structures: Class vs. Struct vs. Record
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5. Everything you need to know about Records in C# (.NET 6 2022)
6. C# 9 Record Types
(Shiv Kumar)
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