Introduction
On November 12, 2014, the day of Visual Studio Connect()
event, Microsoft announced Visual Studio 2015 preview with many new and exciting features for developers for testing purposes. Microsoft announced the new version of C#, C# 6.0 that came with many improvements and new features. One of the newly introduced features of C# 6.0 is the nameof
Operator.
What is nameof Operator
With the introduction of the nameof
operator, the hard-coded string to be specified in our code can be avoided. The nameof
operator accepts the name of code elements and returns a string
literal of the same element. The parameters that the nameof
operator can take can be a class name and all its members like methods, variables and constants and returns the string
literal.
Using string
literals for the purpose of throwing an ArgumentNullException
(to name the guilty argument) and raising a PropertyChanged
event (to name the property that changed) is simple, but error prone because we may spell it wrong, or a refactoring may leave it stale. The nameof
operator expressions are a special kind of string
literal where the compiler checks that you have something of the given name and Visual Studio knows where it refers to, so navigation and refactoring will work easily.
The nameof
Operator can be useful with multiple scenarios, such as INotifyPropertyChanged
, ArgumentNullException
and reflection.
Example 1
string person;
Console.WriteLine(nameof(person));
int x = 2;
Console.WriteLine(nameof(x));
Example 2
public operatornameof(string name)
{
if (name == null)
throw new ArgumentNullException(nameof(name));
else
Console.WriteLine("Name: " + name);
}
Example 3
private int _price;
public int price
{
get
{
return this._price;
}
set
{
this._price = value;
PropertyChanged(this,
new PropertyChangedEventArgs(nameof(this.price))); }
}
Demo Application 1 using Visual Studio 2013
using System;
using System.Text;
namespace CSharpFeatures
{
public class operatornameof
{
public operatornameof(string name, string location, string age)
{
if (name == null)
throw new ArgumentNullException("name");
else
Console.WriteLine("\n Name: " + name);
if (location == null)
throw new ArgumentNullException("location");
else
Console.WriteLine(" Location: " + location);
if (age == null)
throw new ArgumentNullException("age");
else
Console.WriteLine(" Age: " + age);
}
static void Main(String[] args)
{
operatornameof p = new operatornameof("Abhishek", "Ghaziabad", "23");
Console.ReadKey();
}
}
}
Demo Application 1 using Visual Studio 2015 Preview
using System;
using System.Text;
namespace CSharpFeatures
{
public class operatornameof
{
public operatornameof(string name, string location, string age)
{
if (name == null)
throw new ArgumentNullException(nameof(name));
else
Console.WriteLine("Name: " + name);
if (location == null)
throw new ArgumentNullException(nameof(location));
else
Console.WriteLine("Location: " + location);
if (age == null)
throw new ArgumentNullException(nameof(age));
else
Console.WriteLine("Age: " + age);
}
static void Main(String[] args)
{
operatornameof p = new operatornameof("Abhishek", "Ghaziabad", "23");
Console.Read();
}
}
}
Demo Application 2 using Visual Studio 2013
using System;
namespace CSharpFeatures
{
class Operatornameof1
{
static void Main(string[] args)
{
details d = new details();
d.Age = 23;
d.Name = "Abhishek";
Console.WriteLine("\n Name: {0} ", d.Name);
Console.WriteLine(" Age: {0} ", d.Age);
Console.ReadKey();
}
}
class details
{
private string _Name;
public int _Age;
public string Name
{
get { return this._Name; }
set { this._Name = value; }
}
public int Age
{
get { return this._Age; }
set { this._Age = value; }
}
}
}
Demo Application 2 using Visual Studio 2015 Preview
using System;
namespace CSharpFeatures
{
class Operatornameof2
{
static void Main(string[] args)
{
details d = new details();
Console.WriteLine("{0} : {1}", nameof(details.Name), d.Name);
Console.WriteLine("{0} : {1}", nameof(details.Age), d.Age);
Console.ReadKey();
}
}
class details
{
public string Name { get; set; } = "Abhishek";
public int Age { get; set; } = 23;
}
}
Summary
In this tip, we learned how to use the nameof
operator to avoid the use of hard-coded string
s in our code. I hope you liked this new feature of C# 6.0 introduced by Microsoft. Don't forget to read my other articles on the series "A new feature of C# 6.0" . Share your opinion about this feature and how you will use it in your project? Your comments are most welcome.