Use a SortedSet (TreeSet is the default one): SortedSet<String> set=new TreeSet<String>(); set.add(“12”); set.add(“15”); set.add(“5”); List<String> list=new ArrayList<String>(set); No extra sorting code needed. Oh, I see you want a different sort order. Supply a Comparator to the TreeSet: new TreeSet<String>(Comparator.comparing(Integer::valueOf)); Now your TreeSet will sort Strings in numeric order (which implies that it will throw exceptions … Read more
Something like this? Random randomizer = new Random(); String random = list.get(randomizer.nextInt(list.size()));
Safest way – use for loop for (int i = datatable.Rows.Count – 1; i >= 0; i–) { if (true) { datatable.Rows[i].Delete(); } } Don’t forget to AcceptChanges to remove all marked rows: datatable.AcceptChanges();
Why do you need to store it in a List? Do you actually require the data to be ordered or support index-based look-ups? I would suggest storing the data in a Set. If ordering is unimportant you should use HashSet. However, if you wish to preserve ordering you could use LinkedHashSet.
You can also implement the add method via public new void Add(…) in your derived class to hide the existing add and introduce your functionality. Edit: Rough Outline… class MyHappyList<T> : List<T> { public new void Add(T item) { if (Count > 9) { Remove(this[0]); } base.Add(item); } } Just a note, figured it was … Read more
In this thread from 2014, Kotlin community members and JetBrains staff discuss the merits of the different methods find and firstOrNull: https://youtrack.jetbrains.com/issue/KT-5185 While not an official statement, JetBrains’ employee Ilya Ryzhenkov describes it as: I think we can undeprecate find and make it an alias to firstOrNull. Much like indexOf has well-known semantics, find is … Read more
List<T> will be limited to the max of an array, which is 2GB (even in x64). If that isn’t enough, you’re using the wrong type of data storage. You can save a lot of overhead by starting it the right size, though – by passing an int to the constructor. Re your edit – with … Read more
You need to specify the values for the Dictionary var d2 = q.ToDictionary(p => p.NickName, p => p.Name);
Watch out — several answers here are claiming to solve your problem by wrapping a list and checking in add and addAll, but they’re forgetting you can also add to a List via its listIterator. It’s challenging to get a constrained list right, which is why Guava has Constraints.constrainedList to do it for you. But … Read more
otherList.ForEach(o => q.Enqueue(o)); You can also use this extension method: public static void AddRange<T>(this Queue<T> queue, IEnumerable<T> enu) { foreach (T obj in enu) queue.Enqueue(obj); } Queue<int> q = new Queue<int>(); q.AddRange(otherList); //Work!