Merging lists in another list using LINQ c#

Question

I have an author class like this

public class Author : IEquatable<Author>
    {
        public string Name { get; private set; }
        public List<PublicationData> Publications { get; private set }; 

        public Author(string name, List<PublicationData> publications)
        {
            Name = name;
            Publications = publications;
        }

        public override string ToString()
        {
            string lines = Name + "\n";
            foreach (PublicationData publication in Publications)
                lines += publication.ToString() + "\n";
            return lines;
        }

        public bool Equals(Author other)
        {
            return Name.Equals(other.Name);
        }

        public override int GetHashCode()
        {
            return Name.GetHashCode();
        }
    }

And I have publication class like this

public class PublicationData : IEquatable<PublicationData>
    {
        public string Code { get; set; }
        public int Amount { get; set; }
        public int Subscription_Length { get; set; }

        public PublicationData(string name, int amount, int subscription_Length)
        {
            Code = name;
            Amount = amount;
            Subscription_Length = subscription_Length;
        }

        public override string ToString()
        {
            return String.Format($"{Code}, {Amount}, {Subscription_Length}");
        }

        public bool Equals(PublicationData other)
        {
            return Code.Equals(other.Code);
        }

        public override int GetHashCode()
        {
            return Code.GetHashCode();
        }
    }

Then I have a list of authors that look like this:

AuthorA - PublicationA

AuthorB - PublicationB

AuthorB - PublicationC

I want to get something like this as a new object:

AuthorA - PublicationA

AuthorB - PublicationB - PublicationC

I assume the code should look something like this:

var filtered = authors.Select(nn => new Author
            (
                nn.Name,

                // merge publication lists

             )).Distinct()
               .ToList();

I just have no idea how do I do this. Can anyone suggest something?

Does this answer your question? Merge two List<object> into one List in Linq — Hoppeduppeanut
– Hoppeduppeanut, Commented Jun 4, 2020 at 2:10

Guru Stron · Accepted Answer · 2020-06-03 23:50:24Z

4

It seems that you are looking for GroupBy method:

authors
    .GroupBy(a => a.Name)
    .Select(g => new Author(
        g.Key,
        g.SelectMany(ga => ga.Publications).ToList()))

answered Jun 3, 2020 at 23:50

Guru Stron

151k11 gold badges186 silver badges232 bronze badges

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

2 Comments

AtticFizz Over a year ago

Yes, this was exactly what I was looking for, thank you

Guru Stron Over a year ago

@AtticFizz was glad to help!

AnonymousKKYY · Accepted Answer · 2020-06-04 01:40:48Z

1

You can also achieve it via the following code.

var query = from author in authors
            group author by author.AuthorName;
foreach (var group in query)
{
    Console.WriteLine(group.Key);
    // Nested foreach is required to access group items.
    foreach (var g in group)
    {
        Console.WriteLine($"\t{g.Publication}");
    }
}

Here is a document Group query results you can refer to.

answered Jun 4, 2020 at 1:40

AnonymousKKYY

3,7754 gold badges15 silver badges40 bronze badges

Collectives™ on Stack Overflow

Merging lists in another list using LINQ c#

2 Answers 2

2 Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related