C#: Getting maximum and minimum values of arbitrary properties of all items in a list

Question

I have a specialized list that holds items of type IThing:

public class ThingList : IList
{...}

public interface IThing
{
    Decimal         


        

Answer 1

For C# 2.0 and .Net 2.0 you can do the following for Max:

public delegate Decimal GetProperty(TElement element);

public static Decimal Max(IEnumerable enumeration, 
                                    GetProperty getProperty)
{
    Decimal max = Decimal.MinValue;

    foreach (TElement element in enumeration)
    {
        Decimal propertyValue = getProperty(element);
        max = Math.Max(max, propertyValue);
    }

    return max;
}

And here is how you would use it:

string[] array = new string[] {"s","sss","ddsffffd","333","44432333"};

Max(array, delegate(string e) { return e.Length;});

Here is how you would do it with C# 3.0, .Net 3.5 and Linq, without the function above:

string[] array = new string[] {"s","sss","ddsffffd","333","44432333"};
array.Max( e => e.Length);