C# Structures (Structs)

In c#, structures are same as classes, but the only difference is classes are the reference types, and structures are the value types. As a value type, the structures directly contain their value, so their object or instance is stored on the stack, and structures are faster than classes.

 

In c#, the structures can contain fields, properties, member functions, operators, constructors, events, indexers, constants, and even other structure types.

Create Structures in C#

In c#, structures can be created by using struct keyword. Following is the declaration of structure in the c# programming language.

 

public struct users
{
// Properties, Methods, Events, etc.
}

If you observe the above syntax, we defined a structure “users” using struct keyword with public access modifier. Here, the public access specifier will allow the users to create objects for this structure, and inside of the body structure, we can create required fields, properties, methods, and events to use in our applications.

 

Following is the example of defining a structure in the c# programming language.

 

public struct User
{
    public string name;
    public string location;
    public int age;
}

If you observe the above example, we defined a structure called “User” with required fields, and we can add required methods and properties based on our requirements.

C# Structure Initialization

In c#, structures can be instantiated with or without new keyword. Following is the example of assigning values to the variables of structure.

 

User u = new User();
u.name = "Suresh Dasari";
u.location = "Hyderabad";
u.age = 32;

To make use of fields, methods, and events of structure, then it’s mandatory to instantiate a structure with new keyword in c# programming language.

C# Structure with Constructor

In c#, the structures won’t allow us to declare a default constructor or a constructor without parameters. It won’t allow us to initialize fields with values unless they are declared as const or static.

 

Following is the example of defining a structure with parameterized constructor and initializing the constructor fields in the c# programming language.

 

public struct User
{
    public string name, location;
    // Parameterized Constructor
    public User(string a, string b)
    {
        name = a;
        location = b;
    }
}

If you observe the above example, we defined a structure called “User” with required fields and parameterized constructor.

C# Structure with Default Constructor

As discussed, the structures will allow only parameterized constructors, and fields cannot be initialized unless they are declared as const or static.

 

Following is the example of defining a structure with a default constructor and initializing fields with values.

 

struct User
{
    // Compile error
    public string name = "Suresh Dasari";
    public string location;
    public int age;
    // Compile error
    public User()
    {
       location = "Hyderabad";
       age = 32;
    }
}

When we execute the above code, we will get compiler errors because we declared a structure with the default constructor (parameterless) and initialized fields without defining it as const or static.

 

In c#, if we create a structure with the parameterized constructor, then we must need to explicitly initialize all the fields within the constructor before the control is returned to the caller; otherwise, we will get a compile-time error.

 

Following is the example of defining a structure with the parameterized constructor and required fields in the c# programming language.

 

public struct User
{
    public string name, location;
    // Compile Error
    public User(string a)
    {
       name = a;
    }
}

When you execute the above code, we will get a compile-time error because we defined name and location variables, but we assign a value to the only name variable.

 

As discussed, if we create a structure with the parameterized constructor, then we must need to explicitly initialize all the fields before leaving the constructor.

 

Now we will see how to create a structure with fields and parameterized constructors in c# programming language with example.

C# Structure Example

Following is the example of creating a structure with different fields and parameterized constructors in c# programming language with various data members and member functions.

 

using System;

namespace Tutlane
{
    struct User
    {
        public const string name = "Suresh Dasari";
        public string location;
        public int age;
        public User(string a, int b)
        {
           location = a;
           age = b;
        }
    }
    class Program
    {
       static void Main(string[] args)
       {
         // Declare object with new keyword
         User u = new User("Hyderabad", 31);
         // Declare object without new keyword
         User u1;
         Console.WriteLine("Name: {0}, Location: {1}, Age: {2}", User.name, u.location, u.age);
         // Initialize Fields
         u1.location = "Guntur";
         u1.age = 32;
         Console.WriteLine("Name: {0}, Location: {1}, Age: {2}", User.name, u1.location, u1.age);
         Console.WriteLine("\nPress Enter Key to Exit..");
         Console.ReadLine();
       }
    }
}

If you observe the above example, we defined a structure (User) by including required fields, parameterized constructor, and created an instance of structure (User) with and without new keyword to initialize or get field values based on our requirements.

 

When you execute the above c# program, you will get the result as shown below.

 

C# Structures Example Result

 

In c#, by using structures we can implement an interface, but structures cannot inherit from another structure or class.

C# Structure Characteristics

The following are the important characteristics of structures in the c# programming language.

 

  • In c#, structures are value types, and those are defined by using struct keyword.
  • During the structure declaration, the fields cannot be initialized unless defined as const or static.
  • Structures in c# can include fields, properties, member functions, operators, constructors, events, indexers, constants, and even other structure types.
  • Structures cannot include the default constructor (constructor without parameters) or destructor, but it will allow us to declare constructors with parameters.
  • A structure cannot inherit from another structure or class.
  • In c#, the structure can implement interfaces.
  • A structure can be instantiated with or without using a new keyword.

C# Difference between Structure and Class

The following are the difference between structures and classes in the c# programming language.

 

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