How can I filter a list of objects using lambda expression?

Question

I know I shouldn't have id's with the same value. This is just fictitious, so overlook that.

I have:

List<Car> carList = new List<Car>();
carList.Add(new Car() { id = 1, name = "Honda" });
carList.Add(new Car() { id = 2, name = "Toyota" });
carList.Add(new Car() { id = 1, name = "Nissan" });

I want to use Lambda Expression to retrieve all cars that have an id of 1.

Anticipated Result:

-- Id: 1, Name: Honda
-- Id: 1, Name: Nissan

The problem is more filtering an object list based on a foreign key.

Jon Skeet · Accepted Answer · 2010-03-24 15:47:21Z

19

Use LINQ:

IEnumerable<Car> matchingCars = carList.Where(car => car.id == 1);

Using List<T>.FindAll:

List<Car> matchingCars = carList.FindAll(car => car.id == 1);

I would prefer the LINQ approach personally - note that that is lazy, whereas FindAll immediately looks through the whole list and builds a new list with the results.

answered Mar 24, 2010 at 15:47

Jon Skeet

1.5m893 gold badges9.3k silver badges9.3k bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Tim Mahy Over a year ago

I don't agree with the LINQ preference, you first need to know the context of the code before you can decide wether to go lazy initialized or not ....

Jon Skeet Over a year ago

@Tim: I would usually use LINQ with a ToList call afterwards if I wanted eager evaluation, just for a consistency. FindAll could be slightly simpler in some cases, although that does limit you to having a List<T> as a source instead of only requiring IEnumerale<T>.

JaredPar · Accepted Answer · 2010-03-24 15:47:10Z

5

Try this

var match = carList.Where(x => x.id ==1 );

answered Mar 24, 2010 at 15:47

JaredPar

759k152 gold badges1.3k silver badges1.5k bronze badges

Collectives™ on Stack Overflow

How can I filter a list of objects using lambda expression?

2 Answers 2

2 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related