c# - How do I convert Foreach statement into linq expression?

Question

how to convert below foreach into linq expression?

var list = new List<Book>();

foreach (var id in ids)
{
    list.Add(new Book{Id=id});
}

Answer 1

It's pretty straight forward:

var list = ids.Select(id => new Book { Id = id }).ToList();

Or if you prefer query syntax:

var list = (from id in ids select new Book { Id = id }).ToList();

Also note that the ToList() is only necessary if you really need List<Book>. Otherwise, it's generally better to take advantage of Linq's lazy evaluation abilities, and allow the Book objects objects to only be created on demand.