C# と .NET を勉強する

Random random = new Random();
string[] orderIDs = new string[5];
// Loop through each blank orderID
for (int i = 0; i < orderIDs.Length; i++)
{
    // Get a random value that equates to ASCII letters A through E
    int prefixValue = random.Next(65, 70);
    // Convert the random value into a char, then a string
    string prefix = Convert.ToChar(prefixValue).ToString();
    // Create a random number, padd with zeroes
    string suffix = random.Next(1, 1000).ToString("000");
    // Combine the prefix and suffix together, then assign to current OrderID
    orderIDs[i] = prefix + suffix;
}
// Print out each orderID
foreach (var orderID in orderIDs)
{
    Console.WriteLine(orderID);
}

/*
  The following code creates five random OrderIDs
  to test the fraud detection process.  OrderIDs
  consist of a letter from A to E, and a three
  digit number. Ex. A123.
*/
Random random = new Random();
string[] orderIDs = new string[5];

for (int i = 0; i < orderIDs.Length; i++)
{
    int prefixValue = random.Next(65, 70);
    string prefix = Convert.ToChar(prefixValue).ToString();
    string suffix = random.Next(1, 1000).ToString("000");

    orderIDs[i] = prefix + suffix;
}

foreach (var orderID in orderIDs)
{
    Console.WriteLine(orderID);
}

namespace Classes;

public class BankAccount
{
  private static int accountNumberSeed = 1234567890;

  public string Number { get; }

  public string Owner { get; set; }

  public decimal Balance
  {
    get
    {
      decimal balance = 0;
      foreach (var item in allTransactions)
      {
        balance += item.Amount;
      }

      return balance;
    }
  }

  private List<Transaction> allTransactions = new List<Transaction>();

  public BankAccount(string name, decimal initialBalance)
  {
    Number = accountNumberSeed.ToString();
    accountNumberSeed++;

    Owner = name;
    MakeDeposit(initialBalance, DateTime.Now, "Initial balance");
  }

  public void MakeDeposit(decimal amount, DateTime date, string note)
  {
    if (amount <= 0)
    {
      throw new ArgumentOutOfRangeException(nameof(amount), "Amount of deposit must be positive");
    }
    var deposit = new Transaction(amount, date, note);
    allTransactions.Add(deposit);
  }

  public void MakeWithdrawal(decimal amount, DateTime date, string note)
  {
    if (amount <= 0)
    {
      throw new ArgumentOutOfRangeException(nameof(amount), "Amount of withdrawal must be positive");
    }
    if (Balance - amount < 0)
    {
      throw new InvalidOperationException("Not sufficient funds for this withdrawal");
    }
    var withdrawal = new Transaction(-amount, date, note);
    allTransactions.Add(withdrawal);
  }

  public string GetAccountHistory()
  {
    var report = new System.Text.StringBuilder();

    decimal balance = 0;
    report.AppendLine("Date\t\tAmount\tBalance\tNote");
    foreach (var item in allTransactions)
    {
      balance += item.Amount;
      report.AppendLine($"{item.Date.ToShortDateString()}\t{item.Amount}\t{balance}\t{item.Notes}");
    }

    return report.ToString();
  }
}

dotnet add package <name of dependency>

dotnet list package

dotnet list package --include-transitive

dotnet list package --outdated

dotnet remove package <name of dependency>

using ContosoPizza.Models;
using ContosoPizza.Services;
using Microsoft.AspNetCore.Mvc;

namespace ContosoPizza.Controllers;

[ApiController]
[Route("[controller]")]
public class PizzaController : ControllerBase
{
    public PizzaController()
    {
    }

    // GET all action
    [HttpGet]
    public ActionResult<List<Pizza>> GetAll() => PizzaService.GetAll();

    // GET by Id action
    [HttpGet("{id}")]
    public ActionResult<Pizza> Get(int id)
    {
        var pizza = PizzaService.Get(id);

        if (pizza == null)
            return NotFound();

        return pizza;
    }

    // POST action
    [HttpPost]
    public IActionResult Create(Pizza pizza)
    {
        PizzaService.Add(pizza);
        return CreatedAtAction(nameof(Create), new { id = pizza.Id }, pizza);
    }

    // PUT action
    [HttpPut("{id}")]
    public IActionResult Update(int id, Pizza pizza)
    {
        if (id != pizza.Id)
            return BadRequest();

        var existingPizza = PizzaService.Get(id);
        if (existingPizza is null)
            return NotFound();

        PizzaService.Update(pizza);

        return NoContent();
    }

    // DELETE action
    [HttpDelete("{id}")]
    public IActionResult Delete(int id)
    {
        var pizza = PizzaService.Get(id);

        if (pizza is null)
            return NotFound();

        PizzaService.Delete(id);

        return NoContent();
    }
}

using ContosoPizza.Models;

namespace ContosoPizza.Services;

public static class PizzaService
{
    static List<Pizza> Pizzas { get; }
    static int nextId = 3;
    static PizzaService()
    {
        Pizzas = new List<Pizza>
        {
            new Pizza { Id = 1, Name = "Classic Italian", IsGlutenFree = false },
            new Pizza { Id = 2, Name = "Veggie", IsGlutenFree = true }
        };
    }

    public static List<Pizza> GetAll() => Pizzas;

    public static Pizza? Get(int id) => Pizzas.FirstOrDefault(p => p.Id == id);

    public static void Add(Pizza pizza)
    {
        pizza.Id = nextId++;
        Pizzas.Add(pizza);
    }

    public static void Delete(int id)
    {
        var pizza = Get(id);
        if (pizza is null)
            return;

        Pizzas.Remove(pizza);
    }

    public static void Update(Pizza pizza)
    {
        var index = Pizzas.FindIndex(p => p.Id == pizza.Id);
        if (index == -1)
            return;

        Pizzas[index] = pizza;
    }
}

namespace ContosoPizza.Models;

public class Pizza
{
    public int Id { get; set; }
    public string? Name { get; set; }
    public bool IsGlutenFree { get; set; }
}