using linq select from list data where

Question

One Book has list of Tag objects. Using linq I want to select list of books where any tag name contains specified filter.

string genre; // filter
List<Book> books = repository.GetBooks();

foreach(Book book in books.Where(x=>x.Tags.Any())) //I'm stuck here

Ilya Ivanov · Accepted Answer · 2013-11-26 17:00:24Z

6

you need to see if any tag name is equal to the filter:

books.Where(book => book.Tags.Any(tag => tag == genre))

or use Contains method:

books.Where(book => book.Tags.Contains(genre))

assuming Tags property returns a sequence of string. If Tag is a user-defined object, use:

books.Where(book => book.Tags.Any(tag => tag.Name == genre))

answered Nov 26, 2013 at 17:00

Ilya Ivanov

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Comments

p.s.w.g · Accepted Answer · 2013-11-26 17:00:08Z

2

Something like this should work

var results = books.Where(x => x.Tags.Any(t => t.Name == genre))

Or this:

var results = books.Where(x => x.Tags.Select(t => t.Name).Contains(genre))

answered Nov 26, 2013 at 17:00

p.s.w.g

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sjkm · Accepted Answer · 2013-11-26 17:00:16Z

1

try the following

foreach(Book book in books.Where(x=>x.Tags.Any(t => t.Name == "tag-name")))

answered Nov 26, 2013 at 17:00

sjkm

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MarcinJuraszek · Accepted Answer · 2013-11-26 17:00:26Z

1

If Book.Tags is a collection of Tag objects, you should use Any and pass lambda expression:

foreach(Book book in books.Where(x=>x.Tags.Any(t => t.Name == filter)))

If Book.Tags is a collection of strings, you should use Contains method:

foreach(Book book in books.Where(x=>x.Tags.Contains(filter)))

answered Nov 26, 2013 at 17:00

MarcinJuraszek

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