Question

I have a class that has an list<Book> in it, and those Book objects has many many properties.
How can I remove from that list every Book that his level value is different than, for example, 5?

Answer 1

In this particular case, List<T>.RemoveAll is probably your friend:

C# 3:

list.RemoveAll(x => x.level != 5);

C# 2:

list.RemoveAll(delegate(Book x) { return x.level != 5; });