Expression Bodied Indexers And Operators With C# 7

This is my fifth article on C# 7. Followings are the links for my previous articles.

1. Top 10 New Features of C# 7 With Visual Studio 2017
2. Visual Studio 15 Preview First Look & C# 7
3. How to Compile & Test C# 7 Features
4. Understanding ref and out With C# 7

In C# 7, indexers and operator overloading can be written as expression bodied members.

Expression bodied indexers

In C# 7, Indexers can be written as expression bodied members called as “Expression bodied indexers”.

code snippet 

class MyFavColor
{
    private Color[] favColor = new Color[] {Red, Green, Blue,Yellow, Orange};
    public string this[int index] => favColor[index].Name;
}

Complete code with its usage 

using System.Drawing;
using static System.Drawing.Color;
using static System.Console;
using Humanizer;
using static Humanizer.OrdinalizeExtensions;

namespace ExpressionBodiedIndexersExample
{
    class Program
    {
        static void Main(string[] args)
        {
            MyFavColor myFavColor = new MyFavColor();
            WriteLine("My color preferences are :");
            for (int i = 0; i < 5; i++)
            {
                WriteLine($"{(i+1).Ordinalize()} : {myFavColor[i]}");
            }
        }
    }

    class MyFavColor
    {
        private Color[] favColor = new Color[] {Red, Green, Blue,Yellow, Orange};
        public string this[int index] => favColor[index].Name;
    }

}

Output

Expression bodied Operators Overloading

In C# 7, operator overloading can be written as expression bodied members and called as “Expression bodied Operators Overloading”.

Code Snippet 

class Employee
    {
        public int Age { get; set; }
        public int Salary { get; set; }
        public static Employee operator ++(Employee emp) =>
        new Employee { Age = emp.Age + 1, Salary = emp.Salary + 2000 };
    }

Complete code

using static System.Console;

namespace ExpressionbodiedOperatorsExample
{
    class Program
    {
        static void Main(string[] args)
        {
            Employee emp = new Employee { Age = 25, Salary = 80000 };
            emp++;
            WriteLine($"Age: {emp.Age}, Salary : {emp.Salary}");
        }
    }

    class Employee
    {
        public int Age { get; set; }
        public int Salary { get; set; }
        public static Employee operator ++(Employee emp) =>
        new Employee { Age = emp.Age + 1, Salary = emp.Salary + 2000 };
    }
}

If you are looking for an example of other expression bodied members, such as - expression bodied methods, expression bodied properties, expression bodied constructor, expression bodied destructor, expression bodied getters & expression bodied setters, then you can visit here.