C#

public Void MyMethod(string id)
{
 List<Product> _products = new List<Product>();
 List<Category> _categories = new List<Category>();
 
 _products = psc.FindAllProducts().ToList();//Returns a list of Products
 _categories = psc.FindAllCategories().ToList();//Returns a list of Categories
 
 ProductCategory selectedCategory = new ProductCategory();
 StringBuilder errors = new StringBuilder();
 
 try
 {
      var _productCategories = 
      from c in _categories join p in _products 
      on c.ID equals p.CategoryID 
      select new 
      {
         p.ID, p.Name, p.CategoryID, 
         _categoryID = c.ID, _categoryName = c.Name 
      };

      try
      {
        var selectedCat = _productCategories
        .Where(x => x._categoryID ==  Convert.ToInt32(id))
        .SingleOrDefault()._categoryName;
 
        foreach (var pc in _productCategories)
        {
          if (Convert.ToInt32(id) == pc.CategoryID)
          {
            selectedCategory.ProductID = pc.ID;
            selectedCategory.Name = pc.Name;
            selectedCategory.CategoryID = pc._categoryID;
            selectedCategory.CategoryName = pc._categoryName;
          }
        }                  
       }
       catch (Exception ex)
       {
           errors.Append(ex).AppendLine("<br> <br>");
       }
 }
 catch (Exception ex)
 {
    errors.Append(ex).AppendLine("<br"> <br>");
 } 
}

List<Product> _products = psc.FindAllProducts();
List<Category> _categories = psc.FindAllCategories();

var _productCategories = 
    from c in _categories
    join p in _products
    on c.ID equals p.CategoryID
    select new {
        p.ID, p.Name, p.Price,
        p.Quantity, p.CategoryID,
        _categoryID = c.ID,
        _categoryName = c.Name
    };

var selectedProductCategory = _productCategories.SingleOrDefault(x => x._categoryID.ToString() == id);
var selectedCat = selectedProductCategory == null ? null : selectedProductCategory._categoryName;

// Or, with C# 6:
var selectedCat = _productCategories.SingleOrDefault(x => x._categoryID.ToString() == id)?._categoryName;

// Or, to throw an exception if the category doesn't exist:
var selectedCat = _productCategories.Single(x => x._categoryID.ToString() == id)._categoryName;

BillWoodruff wrote:

we need Richard Deeming or Richard MacCutchan to step-up

Richard MacCutchan wrote:

I could possibly give an answer

Duchess to Alice (Alice’s Adventures in Wonderland, Chapter 9)

That’s nothing to what I could say if I chose.

BillWoodruff wrote:

know it is your modesty

BillWoodruff wrote:

we need Richard Deeming or Richard MacCutchan to step-up

Time            Publisher                   Subscriber
----            ---------                   ---------
1               Take a copy                 -
2               -                           Unsubscribe
3               Invoke                      "Check for race condition needed before proceeding"

Pete O'Hanlon wrote:

That's why you take the copy.

Delegate Class (System)[^]:

Delegates are immutable; once created, the invocation list of a delegate does not change.
...
Combining operations, such as Combine and Remove, do not alter existing delegates. Instead, such an operation returns a new delegate that contains the results of the operation, an unchanged delegate, or null.

public class Car
{
    public void createCar(string carname)
    {
        var dt = DateTime.Now;

        Console.WriteLine("\nCar {0} created at: {1} {2}", carname, dt.ToShortDateString(), dt.ToShortTimeString());
    }
}

public class Car
{
    public static Dictionary<string, List<DateTime>> ManufacturerToCars = new Dictionary<string, List<DateTime>>();
    
    public void createCar(string carname)
    {
        var dt = DateTime.Now;
    
        if(! ManufacturerToCars.ContainsKey(carname))
        {
            ManufacturerToCars.Add(carname, new List<DateTime>());
        }
    
        ManufacturerToCars[carname].Add(dt);
    
        Console.WriteLine("\nCar {0} created at: {1} {2}", carname, dt.ToShortDateString(), dt.ToShortTimeString());
    }
}