C# - Datatypes

Datatypes in C#

In C#, data types are broadly classified into two categories: value types and reference types. Value types store data directly, while reference types store a reference to the data's memory address. Understanding how to use different data types effectively is crucial for writing robust and efficient C# programs. Below are explanations and examples of how to use various data types in C#.

Value Types

1. Primitive Data Types

These include basic types like integers, floating-point numbers, and characters.

a.  int: Represents a 32-bit signed integer.

int myInt = 100;

b. double: Represents a double-precision floating-point number.

double myDouble = 99.99;

c.  char: Represents a single 16-bit Unicode character.

char myChar = 'A';

d. bool: Represents a Boolean value (true or false).

bool myBool = true;

Structs

Structs are user-defined value types that can contain multiple related variables.

public struct Point
{
    public int X;
    public int Y;

    public Point(int x, int y)
    {
        X = x;
        Y = y;
    }
}

Point myPoint = new Point(10, 20);

Enumerations

Enums are a distinct type that consists of a set of named constants.

public enum Days { Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday }

Days today = Days.Monday;

Reference Types

Strings

Strings represent sequences of characters and are a special type in C#.

string myString = "Hello, World!";

Arrays

Arrays are collections of variables of the same type.

int[] myArray = new int[5]; // Declaration of an array with 5 elements
myArray[0] = 1;
myArray[1] = 2;
// Alternatively, you can initialize the array directly
int[] myArray2 = { 1, 2, 3, 4, 5 };

Classes

Classes are user-defined reference types that can contain fields, properties, methods, and events.

public class Person
{
    public string Name { get; set; }
    public int Age { get; set; }

    public Person(string name, int age)
    {
        Name = name;
        Age = age;
    }
}

Person person = new Person("John", 30);

Interfaces

Interfaces define a contract that classes or structs can implement.

public interface IAnimal
{
    void MakeSound();
}

public class Dog : IAnimal
{
    public void MakeSound()
    {
        Console.WriteLine("Bark");
    }
}

IAnimal myDog = new Dog();
myDog.MakeSound(); // Output: Bark

Nullable Types

Nullable types are value types that can also represent a null value.

int? nullableInt = null;
nullableInt = 5;

Dynamic Types

Dynamic types are resolved at runtime, allowing for flexible programming.

int? nullableInt = null;
nullableInt = 5;
dynamic dynamicVar = 1;
dynamicVar = "Hello, World!";