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5 C# Evolutions You May Not Know

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5 C# Evolutions You May Not Know

In this article, we will cover some C# evolutions you may not know and, hopefully, they will help you with your project and development.

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1. Safe Navigation Operator ( ? Operator):

The ? operator was introduced with .NET 2.0, with the nullable types that allow variables to have null as a value or to not have one at all. We can test it with the HasValue property.
In C# 6, Microsoft added a new feature to this operator (?) called safe navigation operator.

It's so simple and so useful, let me explain it with an example. We access a child property or method via the navigation operator "." but if you try to navigate into a null variable you will have the famous NullReferenceException. So we must test before accessing or calling any method on this object like this : 

// porsche is an instance of a Car Class
if(porsche!=null && porsche.Name !=null)
  console.Write(porsche.Name); // we can use the Name proprety

// If we want to use the Accelerate Methode
if(porsche!=null)
  porsche.Accelerate(10);

With safe navigation we can do this : 

string nom = porsche?.Name ; 

// and to call Accelerate()
porsche?.Accelerate(); 

2. Three Ways to Build a String (String Interpolation): 

  • There are many ways to build a string, The best and faster one, if we want to talk about execution time, is the StringBuilder: 

// Create a StringBuilder that expects to hold 50 characters.
// Initialize the StringBuilder with "ABC".
StringBuilder sb = new StringBuilder("ABC", 50);

// Append three characters (D, E, and F) to the end of the StringBuilder.
sb.Append("DEF");

// Display the string
Console.WriteLine(sb.ToString());
  • If we have some parameter to put in our string we can use the String.Format,like this:

decimal temp = 20.4m;
string s = String.Format("The temperature is {0}°C.", temp);
Console.WriteLine(s);
// Displays 'The temperature is 20.4°C.'

In this method, there are many options to transform your string in a specific format.

You can see all the options in this link

  • The evolution in C# 6 is the new string interpolation syntax:

string name = Joe ;
string hours = "11:00";

Console.WriteLine($"Name = {name}, hours = {hours}");

3. An Elegant Way to Structure an Object (Tuple):

(This is just an example of use)
The majority of programming languages support functions and procedures used with the standard format (a signature, parameters, and a return object). Generally, if we want to return many values or objects, we are obliged to use a list of objects or an array. To do otherwise, C# 6 offered us an elegant structure called a Tuple.

MSDN defines a Tuple as : 

A tuple is a data structure that has a specific number and sequence of elements. An example of a tuple is a data structure with three elements (known as a 3-tuple or triple) that is used to store an identifier such as a person's name in the first element, a year in the second element, and the person's income for that year in the third element. 

There are many ways to create a Tuple.

  • Use the classic constructor, new:

Tuple<string, string,string> person = new Tuple<string, string,string>("Jhon","Doe","5555");
Console.WriteLine("Full Name: {0} {1}  ", person.Item1, person.Item2);
Console.WriteLine("PIN: {0} ", person.Item3);
  • Use The static method, Create:

// Create a 5-tuple.
var population = Tuple.Create("Tunisia", 6999, 54462, 9888, 5258456);
// Display the first and last elements.
Console.WriteLine("Population of {0} in 2013: {1:N0}",
                  population.Item1, population.Item5);
// The example displays the following output:
//       Population of Tunisia in 2013: 5,258,456
  • In C# 7, there is a new way to declare Tuples and get rid of Item1 and Item2 and name them with a significant keyword.

public (string name, string location, string population) GetCountry() {
// fin a person in a list and return
return ("Tunisia","North Africa","5258456") ; 
}

var country = GetCountry(); 

Console.WriteLine("Population of {0} - {1} in 2013: {2:N0}",
                  country.name,country.location, country.population);
// The example displays the following output:
//       Population of Tunisia - North Africa in 2013: 5,258,456

4 . An Enumerable Function's Params:

The params keyword give you the possibility to have a variable method's params number and pass a list of objects in the method call. It's a useful feature when you don't have any idea of the number of objects passed in a parameter. 

public void PrintValues (params string [] values)
{
foreach (var value in values)
  Console.WriteLine(value);
}

PintValues("Hello","this","is","a","test"); 

// Consol print 
// Hello
// this
// is
// a
// test


5. Static Imports:

With C# 6, you can import a dependency with the keyword static. In this way, you can use any method in the imported reference without specifying the class.

using static System.Math;
...
double x = 3;
double y = 4;
double distance = Sqrt(x * x + y * y);

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Topics:
.net ,c# ,web dev ,.net application development

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