CODEWITHSUNDEEP
c#.net
abdalrahman makahleh
abdalrahman makahleh

Reputation: 53

How can I exclude data from list based on another array?

Is there any way to exclude data from a list depending on whether the list contains one of the ID in another array?

For example, given:

int[] excludedCities = new int[] { 342, 344, 22, 19, 2 };
List<Cities> cities = new List<Cities>();

I want to remove the cities with the id in excludedCities array. Is there an easier way than iterating the list?

Upvotes: 1

Views: 675

Answers (2)

Ousmane D.
Ousmane D.

Reputation: 56433

If you're happy removing the elements from the cities list then you can do:

cities.RemoveAll(c => excludedCities.Contains(c.Id));

otherwise, you can do:

List<Cities> result = cities.Where(c => !excludedCities.Contains(c.Id))
                            .ToList();

Upvotes: 1

glenebob
glenebob

Reputation: 1973

HashSet<int> excludedCityHash = new HashSet<int>(excludedCities);
IEnumerable<City> filtered = cities.Where(city => !excludedCityHash.Contains(city.ID));

You can do just:

IEnumerable<City> filtered = cities.Where(city => !excludedCities.Contains(city.ID));

... but for more than a small handful of excluded cities, performance will start to suffer.

Upvotes: 1

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