Expression - Bodied Methods in C# 6

In this blog you will learn Expression-bodied Methods in C# 6.

In C# 6 Microsoft introduces a new feature Expression-bodied Methods which is very similar to and inspired by anonymous lambda expression. But there are some differences between these two.

In case of Expression-bodied methods it must have return type, name and returned expression.

We can use access modifiers (private, public, protected, internal and protected internal) with expression-bodied method. We can declare it as virtual, static or it can also override its parent class method. It can be asynchronous if it is returning void.

Example 1: Expression-bodied method having access modifier as public and return type string,

public string GetUserDetails() => $"{UserId} + {UserName} + {EmailId} + {ContactNumber}";

Complete Code

class User
{
   public int UserId { get; set; }
   public string UserName { get; set; }
   public string EmailId { get; set; }
   public string ContactNumber { get; set; }
   public string GetUserDetails() => $"{UserId} + {UserName} + {EmailId} + {ContactNumber}";
}

In the above example GetUserDetails() method is having access modifier public and return type string. 

Example 2: Override an existing method using Expression-bodied Method,

public override string ToString()=> $"{UserId} + {UserName} + {EmailId} + {ContactNumber}";

Complete code

class User
{
   public int UserId { get; set; }
   public string UserName { get; set; }
   public string EmailId { get; set; }
   public string ContactNumber { get; set; }
   public string GetUserDetails() => $"{UserId} + {UserName} + {EmailId} + {ContactNumber}";
   public override string ToString()=> $"{UserId} + {UserName} + {EmailId} + {ContactNumber}";
}

Example 3: Creating a Virtual method using Expression-bodied Method and override it.

public virtual string GetUserDetails() => $"{UserId} + {UserName} + {EmailId} + {ContactNumber}";
public override string GetUserDetails() => $"{UserId} + {UserName} + {EmailId} + {ContactNumber} + {Rank}";

Complete code

class User
{
  public int UserId { get; set; }
  public string UserName { get; set; }
  public string EmailId { get; set; }
  public string ContactNumber { get; set; }
  public virtual string GetUserDetails() => $"{UserId} + {UserName} + {EmailId} + {ContactNumber}";
  public override string ToString()=> $"{UserId} + {UserName} + {EmailId} + {ContactNumber}";
}
  class SilverUser : User
  {
     public int Rank { get; set; }
     public override string GetUserDetails() => $"{UserId} + {UserName} + {EmailId} + {ContactNumber} + {Rank}";
  }