Your observation is spot on – in fact, it mirrors one made by Mads Torgersen, a Microsoft C# Language PM. Mads made a post in October 2006 on this subject titled What Is a Collection? in which he wrote: Admitted, we blew it in the first version of the framework with System.Collections.ICollection, which is next …
As other people have mentioned, ArrayList has a constructor that takes a collection of items, and adds all of them. Here’s the documentation: http://java.sun.com/javase/6/docs/api/java/util/ArrayList.html#ArrayList%28java.util.Collection%29 So you need to do: ArrayList<MyNode> myNodeList = new ArrayList<MyNode>(this.getVertices()); However, in another comment you said that was giving you a compiler error. It looks like your class MyGraph is a …
Yes, use the HttpRequest.QueryString collection: Gets the collection of HTTP query string variables. You can use it like this: foreach (String key in Request.QueryString.AllKeys) { Response.Write(“Key: ” + key + ” Value: ” + Request.QueryString[key]); }
You can do this widgets2.Where(y=>widget1.Any(z=>z.TypeID==y.TypeID));
All of these interfaces inherit from IEnumerable, which you should make sure you understand. That interface basically lets you use the class in a foreach statement (in C#). ICollection is the most basic of the interfaces you listed. It’s an enumerable interface that supports a Count and that’s about it. IList is everything that ICollection …
Consider the following example: You have a simple data structure Data with a single property of type List. class Data(val items : List<String>) val dataObjects = listOf( Data(listOf(“a”, “b”, “c”)), Data(listOf(“1”, “2”, “3”)) ) flatMap vs. map With flatMap, you can “flatten” multiple Data::items into one collection as shown with the items variable. val items: …
I am wondering why the Framework doesn’t contain structures as Tree and Graph which are basic collections. Both can be regarded as sub types of Collection. This is a good question. I think it simply boils down to scoping. The core features that Collections API provides classes for are: iteration order: Lists and sorted maps …
ListMap implements an immutable map using a list-based data structure, and thus preserves insertion order. scala> import collection.immutable.ListMap import collection.immutable.ListMap scala> ListMap(1 -> 2) + (3 -> 4) res31: scala.collection.immutable.ListMap[Int,Int] = Map(1 -> 2, 3 -> 4) scala> res31 + (6 -> 9) res32: scala.collection.immutable.ListMap[Int,Int] = Map(1 -> 2, 3 -> 4, 6 -> 9) …
Use filter: scala> val collection = List(1,2,3,4,5) collection: List[Int] = List(1, 2, 3, 4, 5) // take only that values that both are even and greater than 3 scala> collection.filter(x => (x % 2 == 0) && (x > 3)) res1: List[Int] = List(4) // you can return this in order to check that there …
Map.Entry is a key and its value combined into one class. This allows you to iterate over Map.entrySet() instead of having to iterate over Map.keySet(), then getting the value for each key. A better way to write what you have is: for (Map.Entry<String, JButton> entry : listbouton.entrySet()) { String key = entry.getKey(); JButton value = …