If you want to abstract away some of the logic into a reusable extension method, you can add the following:


```cs
public static IEnumerable<TSource> DistinctBy<TSource, TKey>
    (this IEnumerable<TSource> source, Func<TSource, TKey> keySelector)
{
    HashSet<TKey> seenKeys = new HashSet<TKey>();
    foreach (TSource element in source)
    {
        if (!seenKeys.Contains(keySelector(element)))
        {
            seenKeys.Add(keySelector(element));
            yield return element;
        }
    }
}
```

This will work for both single properties and composite properties and return the first
matching element

```cs
// distinct by single property
var productsByTitle = animals.DistinctBy(a => a.Title);

// distinct by multiple properties
var productsByTitleAndColor = animals.DistinctBy(a => new { a.Title, a.Color} );
```

One benefit to this approach (instead of group by + first) is you can return a yieldable enumerable in case you have later criteria that don't force you to loop through the entire collection

**Further Reading**: [linq query to return distinct field values from a list of objects][1]

[1]: https://stackoverflow.com/a/35795985/1366033


How can I using c# and Linq to get a `result` from the next list:

     var pr = new List<Product>()
       {
           new Product() {Title="Boots",Color="Red",    Price=1},
           new Product() {Title="Boots",Color="Green",  Price=1},
           new Product() {Title="Boots",Color="Black",  Price=2},
         
           new Product() {Title="Sword",Color="Gray", Price=2},
           new Product() {Title="Sword",Color="Green",Price=2}
       };

 
  `Result`:

            {Title="Boots",Color="Red",  Price=1},               
            {Title="Boots",Color="Black",  Price=2},             
            {Title="Sword",Color="Gray", Price=2}
               

I know that I should use `GroupBy` or `Distinct`, but understand how to get what is needed
 

       List<Product> result = pr.GroupBy(g => g.Title, g.Price).ToList(); //not working
       List<Product> result  = pr.Distinct(...);
Please help