CODEWITHSUNDEEP
c#listmethods
Sturm
Sturm

Reputation: 4125

List filtering variant

Is there an easy way (maybe a method) of retrieving an object from a list depending on if one of its property matches the requested one?

For example, if I have List<Animal> and the Animal class has a property Size. How could I get the objects from a list with Size=42? It's like filtering but isn't there an easier and faster way of doing it? Insted of using ICollectionView.

public Animal getAnimalWithSize42 (List<Animal> animList)
{
    List<Animal> size42Animals = new List<Animal>
    foreach (Animal anim in animList)
    { 
        if(anim.Size==42)
       size42Animals.Add(anim);
    }
    return size42Animals;
}

Is this some kind of implemented function?

Upvotes: 1

Views: 67

Answers (4)

Mike Corcoran
Mike Corcoran

Reputation: 14565

You can use LINQ, that's generally the easiest way. Something like this maybe:

IEnumerable<Animal> getAnimalWithSize42(IEnumerable<Animal> animList)
{
    return animList.Where(animal => animal.Size == 42);
}

If you wanted to be slick - you could even let the caller pass in what they want to retrieve:

IEnumerable<Animal> getAnimalsMeetingCriteria(IEnumerable<Animal> animals, Func<Animal, bool> filter)
{
    return animals.Where(filter);
}

Make sure you add a reference to System.Linq in the file that needs to use this.

Upvotes: 5

apparat
apparat

Reputation: 1954

LINQ is ideal for this purpose:

public Animal getAnimalWithSize42 (List<Animal> animList)
{
    return animList.Where(a => a.Size == 42);
}

Upvotes: 1

Pierre-Luc Pineault
Pierre-Luc Pineault

Reputation: 9201

Use LINQ to do it.

List<Animal> size42Animals = animList.Where(anim => anim.Size == 42).ToList();

Upvotes: 1

Paolo Tedesco
Paolo Tedesco

Reputation: 57222

You can use LINQ:

return animList.Where(anim => anim.Size == 42);

Upvotes: 4

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