Fastest way to Remove Duplicate Value from a list by lambda

Question

what is fastest way to remove duplicate values from a list. Assume `List longs = new List { 1, 2, 3, 4, 3, 2, 5 };` So I am interesting in use lambda to remove duplicate and returned : `{1, 2, 3, 4, 5}`. What is your suggestion?

Accepted Answer

The easiest way to get a new list would be: ``` List unique = longs.Distinct().ToList(); ``` Is that good enough for you, or do you need to mutate the existing list? The latter is significantly more long-winded. Note that `Distinct()` isn't guaranteed to preserve the original order, but in the current implementation it will - and that's the most natural implementation. See my Edulinq blog post about `Distinct()` for more information. If you don't need it to be a `List`, you could just keep it as: ``` IEnumerable unique = longs.Distinct(); ``` At this point it will go through the de-duping each time you iterate over `unique` though. Whether that's good or not will depend on your requirements.

Fastest way to Remove Duplicate Value from a list<> by lambda

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