user137348 user137348 - 2 months ago 5x
C# Question

Check IEnumerable<T> for items having duplicate properties

How to check if an IEnumerable has two or more items with the same property value ?

For example a class

public class Item
public int Prop1 {get;set;}
public string Prop2 {get;set;}

and then a collection of type

I need to return false if there are items with duplicate values in Prop1.


I think this method will work.

public static bool ContainsDuplicates<T>(this IEnumerable<T> source, Func<T, T1> selector)
    var d = new HashSet<T1>();
    foreach(var t in source)
            return true;
    return false;