veggerbyFinding unique values from a list of objects
Posted: March 28, 2008 Filed under: .NET General Leave a comment »I have several times had to get a unique list of values from a set of objects, for example the simplest way to populate a filter dropdown with possible names of the people in a list of persons. A simple/nifty little routine that does that:
Based on an list (IEnumerable<S>) loop through them all, using a delegate get the value/property (of type T) from the object (of class S) and return all uniques hereof (using basic object equality – Equals)
public static IEnumerable<T> FindUniques<T, S>(IEnumerable<S> list, ValueDelegate<T, S> valueDelegate)
{
List<T> result = new List<T>();
foreach (S item in list)
{
T value = valueDelegate(item);
if (!result.Contains(value))
{
result.Add(value);
yield return value;
}
}
}
