Consuming a C# class in F#

F# and C# can work together pretty easily. Say that your domain classes are contained in a C# class library called Project.Domains. Let’s take the following Product class as an example:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Project.Domains
{
	public class Product
	{
		public Product(string name, int price)
		{
			Name = name;
                        Price = price;
		}

		public string Name { get; }
		public int Price { get; }

		public double CalculateDiscountedPrice(double percentageOff)
		{
			double discount = Price * percentageOff;
			return Price - discount;
		}
	}
}

You can add a project reference to the Project.Domains C# library from an F# project. Rebuild the solution and then you can open the domain library with the F# open statement. It has the same purpose as a C# using statement:

open Project.Domains

From then on the C# classes in the Project.Domains library can be consumed with F# syntax:

let product = new Product("Table", 1000)
let discountedPrice = product.CalculateDiscountedPrice(0.2)
printfn "Discounted price: %f" discountedPrice

discountedPrice will be 800 as expected.

View all F# related articles here.