check duplicate list c# code example

Example 1: c# linq check for duplicate

var duplicates = list.GroupBy(x => x.Key).Any(g => g.Count() > 1);

Example 2: c# see if list contains any duplicates

var list = new List<string>();

// Fill the list

if(list.Count != list.Distinct().Count())
{
     // Duplicates exist
}