How to implement coin jar in c# using Rest API?

Guest User

6y2kAlgorithms in C#

Hi Team

I need some help with my requirement to implement coin jar in c# using rest api. My requirement are as below;

"coin jar only accept latest us coinage, must have volume of 42 fluids ounces"

"must have a counter to keep track of the total amount of money collected"

"reset the count back to $0.00."

My logic so far is as follows in c# using rest api

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Web.Http;
namespace CoinJarAPI.Controllers
{
public class CoinJarController : ApiController
{
// GET: api/CoinJar
public IEnumerable<string> Get()
{
return new string[] { "value1", "value2" };
}
// GET: api/CoinJar/5
public string Get(int id)
{
return "value";
}
// POST: api/CoinJar
public void Post([FromBody]string value)
{
}
// PUT: api/CoinJar/5
public void Put(int id, [FromBody]string value)
{
}
// DELETE: api/CoinJar/5
public void Delete(int id)
{
}
}
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace CoinJarAPI.Interface
{
interface ICoinJar
{
void AddCoin(ICoin coin);
decimal GetTotalAmount();
void Reset();
}
public interface ICoin
{
decimal Amount { get; set; }
decimal Volume { get; set; }
}
}
using CoinJarAPI.Interface;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
namespace CoinJarAPI.Repository
{
public class Repository : ICoinJar
{
public void AddCoin(ICoin coin)
{
throw new NotImplementedException();
}
public decimal GetTotalAmount()
{
throw new NotImplementedException();
}
public void Reset()
{
throw new NotImplementedException();
}
}
}

6 Replies

Know the answer? Post it — somebody with the same question will find it here.

Mario Scheeren5y ago
Accepted answer
You should read about DEPENDENCY INJECTION!!!
Startup.cs
public class Startup
{
/* .... */

// This method gets called by the runtime. Use this method to add services to the container.
// For more information on how to configure your application, visit https://go.microsoft.com/?LinkID=398940
public void ConfigureServices(IServiceCollection services)
{

           services.AddControllersWithViews();
           services.AddRazorPages();

           // THIS IS IMPORTANT
           services.AddSingleton(provider => new CoinJar());
       }

     /* .... */
Controller:
[ApiController]
[Route("[controller]")]
public class MyControllerController : ControllerBase
{
     private readonly ILogger logger;
     private readonly CoinJar coinJar;

     public MyControllerController(ILogger logger, CoinJar coinJar)
     {
         this.logger = logger;
         this.coinJar = coinJar;
     }
     [HttpPost]
     public void AddCoin([FromBody]eCoinType coinType, [FromBody]int count = 1)
     {
        this.coinJar.AddCoin(coinType, count);
     }
     [HttpGet]
     public decimal Amount()
     {
        return this.coinJar.GetTotalAmount();
     }
}
Now get a clue how this wiorks?
+1
Guest User5y ago
Thanks so much for your help
+1
Mario Scheeren5y ago
Hi,

it was an example I added to one of my Blazor-Projects.

so this

"services.AddRazorsPages()"

only applies to a Blazor-Project, bur still it shows how Dependency Injection works.
+1
Guest User5y ago
Hi Mario

Last question, on Startup.cs

services.AddRazorsPages().// must this method should exist throughout the web-pages if you dont there is no need to be defined here or must?
+1
Guest User6y ago
Hi Mario

Where do i add this object? CoinJarController? How do i then expose Rest API endpoints of

1.add a coin
2.get the total amount
3.reset the coins

Because when i want to ran it on the browser its not showing, need some bit of a help please on this one.
+1
Mario Scheeren6y ago
Add an Instance of your CoinJar to your services so you can add it using Dependency Injection.
enum eCoinType
{
    Cent = 1,
    Nickel = 5,
    Dime = 10,
    Quarter = 25,
    Half = 50,
    Large = 100
}

class Coins
{
    public readonly eCoinType CoinType;
    public int Amount { get; set; } = 0;

    public Coins(eCoinType coinType)
    {
        CoinType = coinType;
    }
}

class CoinJar
{
    private readonly Coins[] coins = Enum.GetValues(typeof(eCoinvType)).Cast().Select(x => new Coins(x)).ToArray();

    public CoinJar()
    {
    }

    public void AddCoin(eCoinType coinType, int count = 1)
    {
        coins.First(x => x.CoinType == coinType).Amount += count;
    }

    public decimal GetTotalAmount()  => coins.Select(c => (decimal)c.CoinType * (decimal)c.Amount).Sum() / 100m;

    public void Reset()
    {
        foreach(var c in coins)
        {
            c.Amount = 0;
        }
    }
}
+2