order array descending in c # with lambda [duplicate]

Question

I want order to object array by one of its variables "n_common" and this gives me error:

you can´t convert Lambda expressions in the type array because is not a type delegate.

cartesian_product.Sort((a, b) => -1 * a.n_common.CompareTo(b.n_common));

I want to order descending my "Pair" object that contains 3 variable "p", "q" and "n_common", it should be ordered by the "n_common", the cartesian_product is a array of Pair object.

I am not working with Linq just with Lambda expression or at least that is how I understand it anyway I put the linq in the header and the problem continues

No because I am not working with Linq just with Lambda expression or at least that is how I understand it anyway I put the linq in the header and the problem continues — CoolLife
– CoolLife, Commented Mar 10, 2019 at 22:43
What is the type of cartisian_product? What do you expect your lambda to do. I believe that Sort is expecting a delegate that takes an instance of the type the collection is collecting and return a value that can be sorted. Something like people.Sort(p => p.Age) would take a collection of persons (in a variable people and sort them by age. In your case, the delegate is specifying a function that takes two parameters). — Flydog57
– Flydog57, Commented Mar 10, 2019 at 23:18

Amir Molaei · Accepted Answer · 2019-03-10 23:10:55Z

0

Sort is a static method, so it must be called from the class Array not an instance. Try this:

Array.Sort(cartesian_product, (a, b) => -1 * a.n_common.CompareTo(b.n_common));

answered Mar 10, 2019 at 23:10

Amir Molaei

3,8601 gold badge20 silver badges22 bronze badges

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

Comments

user1666620 · Accepted Answer · 2019-03-10 22:39:52Z

0

At the top of your class add using System.Linq; and using System.Data.Entity;.

answered Mar 10, 2019 at 22:39

user1666620

4,81821 silver badges28 bronze badges

2 Comments

CoolLife Over a year ago

No because I am not working with Linq just with Lambda expression or at least that is how I understand it anyway I put the linq in the header and the problem continues

Flydog57 Over a year ago

The various extension methods that take a lambda expression (for example Sort) are defined in System.Linq. You may not think you are using LINQ, but you are.

Collectives™ on Stack Overflow

order array descending in c # with lambda [duplicate]

2 Answers 2

Comments

2 Comments

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

2 Comments

Linked

Related