HomeController.cs

using System;
using Microsoft.AspNetCore.Mvc;

namespace ConsoleApplication
{
    public class HomeController
    {
        [HttpGet("/{name}")]
        public string Index(string name)
        {
            return $"Hello {name}";
        }

        [HttpGet("/")]
        public string Index()
        {
            return "Hello ASP.NET Core MVC";
        }
    }
}