Struct in C#: Syntax, And Usage

Introduction

A value type and an assortment of variables with various data types grouped together under one unit is called a structure. Given that they are both user-defined data types and may store a large number of different data types, they are nearly identical to classes. Pre-defined data types can be used with C#. User-Defined Data Types, as they are also called, are data types that the user may need to define on occasion. Even though it is a value type, the user can alter it to suit their needs, which is why it is also known as a user-defined data type.

Defining Structure

The struct keyword in C# is used to define structure. One can define a structure that contains various data kinds by using the struct keyword. Constructors, constants, fields, methods, properties, indexers, events, and other elements can also be found in a structure.

Syntax

AccessModifier struct structureName
{

   // Fields 
   // Parameterized constructor 
   // Constants 
   // Properties 
   // Indexers 
   // Events 
   // Methods etc.
   
}

Example

public struct Employee
{
    public int Id;
    public string Name;
    public int Rank;
}

var emp = new Employee
{
    Name = "Jaimin Shethiya",
    Rank = 183,
    Id = 1
};

Console.WriteLine("{0} - {1}", nameof(emp.Id), emp.Id);
Console.WriteLine("{0} - {1}", nameof(emp.Name), emp.Name);
Console.WriteLine("{0} - {1}", nameof(emp.Rank), emp.Rank);

Constructor in Structure

A parameterless constructor is not allowed in a struct. It can only have a static constructor or parameterized constructors.

public struct Employee
{
    public int Id;
    public string Name;
    public int Rank;

    public Employee(int id, string name, int rank)
    {
        Id = id;
        Name = name;
        Rank = rank;
    }
}

var emp = new Employee(1, "Jaimin Shethiya", 183);

Console.WriteLine("{0} - {1}", nameof(emp.Id), emp.Id);
Console.WriteLine("{0} - {1}", nameof(emp.Name), emp.Name);
Console.WriteLine("{0} - {1}", nameof(emp.Rank), emp.Rank);

Methods and Properties in Structure

Similar to classes, structs can have methods, auto-implemented properties, and other attributes.

public struct Employee
{
    // Properties
    public int Id { get; set; }
    public string Name { get; set; }
    public int Rank { get; set; }

    // Method
    public void SetEmployee()
    {
        Id = 1;
        Name = "Jaimin Shethiya";
        Rank = 183;
    }
}

var emp = new Employee();
emp.SetEmployee();

Console.WriteLine("{0} - {1}", nameof(emp.Id), emp.Id);
Console.WriteLine("{0} - {1}", nameof(emp.Name), emp.Name);
Console.WriteLine("{0} - {1}", nameof(emp.Rank), emp.Rank);

Static Constructor in Struct

The following structure includes the static method.

public struct Employee
{
    public int Id;
    public string Name;
    public int Rank;

    public Employee(int id, string name, int rank)
    {
        Id = id;
        Name = name;
        Rank = rank;
    }

    public static Employee GetEmployee()
    {
        Console.WriteLine("Static method called.");
        Console.WriteLine();
        return new Employee(1, "Jaimin Shethiya", 183);
    }
}

// Static method
var emp = Employee.GetEmployee();

Console.WriteLine("{0} - {1}", nameof(emp.Id), emp.Id);
Console.WriteLine("{0} - {1}", nameof(emp.Name), emp.Name);
Console.WriteLine("{0} - {1}", nameof(emp.Rank), emp.Rank);

Events in Structure

Events can be contained in a structure to alert subscribers to a certain action. There is an event in the following structure.

public struct Employee
{
    private string _name;
    private int _rank;

    public int Id;
    public string Name
    {
        get { return _name; }
        set
        {
            _name = value;
            Changed(_name);
        }
    }
    public int Rank
    {
        get { return _rank; }
        set
        {
            _rank = value;
            Changed(_rank);
        }
    }
    public event Action<object> Changed;
}
var emp = new Employee();
// Event handle
emp.Changed += StructureEventHandler;
emp.Id = 1;
emp.Name = "Jaimin Shethiya";
emp.Rank = 183;
Console.WriteLine();
Console.WriteLine("{0} - {1}", nameof(emp.Id), emp.Id);
Console.WriteLine("{0} - {1}", nameof(emp.Name), emp.Name);
Console.WriteLine("{0} - {1}", nameof(emp.Rank), emp.Rank);
// Logged the value
static void StructureEventHandler(object value)
{
    Console.WriteLine("Changed value: {0}", value);
}

Copy Structure

The "=" (Assignment) operator in C# allows the user to copy one structure object into another.

var emp = new Employee
{
    Id = 1,
    Name = "Jaimin Shethiya",
    Rank = 183
};

// Declare the new employee
Employee employee;

// Copy the employee data
employee = emp;
Console.WriteLine();
Console.WriteLine("{0} - {1}", nameof(employee.Id), employee.Id);
Console.WriteLine("{0} - {1}", nameof(employee.Name), employee.Name);
Console.WriteLine("{0} - {1}", nameof(employee.Rank), employee.Rank);

Summary

Constructors, constants, fields, methods, properties, indexers, operators, events, nested types, and events are examples of structure elements.

A parameterless constructor or destructor cannot be included in a structure.

Similar to classes, structs can implement interfaces.

A structure cannot be the basis of another class or inherit another structure.

It is not possible to designate struct members as abstract, sealed, virtual, or protected.

We learned the new technique and evolved together.

Happy coding!