Question

Assuming I have a method which accepts an IList or similar thing as a parameter:

public void JiggleMyList(IList<string> list)...

Is there an easy way that I can pass in string members of a list of objects?

I mean, if for example, I have a list of Person objects which expose a string property called FullName, is there a quick way to stuff the FullNames of all the Person objects into the method parameter, or do I have to create a new List and iterate through the Person objects:

List<string> fullNames = new List<string>;
foreach (Person person in people)
{
  fullNames.Add(person.FullName);
}
JiggleMyList(fullNames);

I come across this all the time, and it would be nice if there was a shortcut.

Many thanks

David

Answer 1

If you’re using .NET 3.5, then you can write this using LINQ:

JiggleMyList(people.Select(p => p.FullName).ToList());

The Select method takes a lambda expression that is used to convert each object from the source collection to some new value and these new values are collected into IEnumerablt<T> type. The ToList extension method converts this to List<T>.

Alternatively, you can write the same thing using query syntax:

JiggleMyList((from p in people select p.FullName).ToList());

Similar feature is also available in .NET 2.0 (C# 2.0) and you could use anonymous delegate instead of (more elegant) lambda expressions:

JiggleMyList(people.ConvertAll(delegate (Person p) { return p.FullName; }));