Question

From Parameter to Property?

public class ConcatenateListTMember
{
    public static void Test()
    {
        var someList = new List<AnyClass>();
        someList.Add(new AnyClass("value1"));
        someList.Add(new AnyClass("value2"));
        Console.WriteLine(Concatenate(someList, "SomeProperty"));
        Console.ReadLine();
    }

    static string Concatenate<T>(List<T> list, string specifiedPropertyOfT)
    {
        string output = String.Empty;
        // TODO: Somehow concatenate all the specified property elements in the list?
        return output;
    }
}

internal class AnyClass
{
    public AnyClass(string someProperty)
    {
        SomeProperty = someProperty;
    }

    public string SomeProperty { get; set; }
}

How might it be possible to implement the generic method in this code sample?

• Please note that specifiedPropertyOfT does not have to be a string if the same aim can be achieved using another type.
• Ideally, reflection would not be needed 🙂

Answer 1

Even better – an extension method:

static string Concatenate<T>(this IEnumerable<T> list, Func<T,string> func)
{
    return String.Join("",list.Select(func));
}

Usage:

someList.Concatenate(i => i.SomeProperty);

Live example: http://rextester.com/runcode?code=LRA78268