C# 6 is expected to simplify writing properties and methods that involve a single expression. Consider this property exposing a backing field, for instance:
private string firstName;
public string FirstName
{
get
{
return this.firstName;
}
}
We may now write this as:
private string firstName;
public string FirstName => firstName;
And this is also quite handy for more complex properties:
public string FullName => string.Format("{0} {1}", this.firstName, this.lastName);
It works pretty nicely with indexers, even though the C# feature descriptions (PDF) document says it shouldn’t work in the current CTP:
public class Inventory
{
private string[] inventory = new string[10];
public string this[int index] => this.inventory[index];
public void Put(int index, string item)
{
this.inventory[index] = item;
}
}
The expression-bodied members feature gives you a pretty convenient way to write getter-only properties. However, this syntax isn’t restricted to properties alone; you can also use it with methods. The following examples are from the official C# feature descriptions (PDF):
public Point Move(int dx, int dy) => new Point(x + dx, y + dy);
public static Complex operator +(Complex a, Complex b) => a.Add(b);
public static implicit operator string(Person p) => p.First + " " + p.Last;
void methods, which don’t return anything, may also take advantage of this syntax. In fact, we can quite easily rewrite the Inventory class’s operations using expression-bodied methods:
public class Inventory
{
private string[] inventory = new string[10];
public string this[int index] => this.inventory[index];
public void Put(int index, string item) => this.inventory[index] = item;
public void RemoveAt(int index) => this.inventory[index] = null;
}
You can appreciate how this can make classes much more concise.
