A very simple & quick question on Java libraries: is there a ready-made class that implements a Queue with a fixed maximum size – i.e. it always allows addition of elements, but it will silently remove head elements to accomodate space for newly added elements. Of course, it’s trivial to implement it manually: import java.util.LinkedList; … Read more
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While we can inherit from base class/interface, why can’t we declare a List<> using same class/interface? interface A { } class B : A { } class C : B { } class Test { static void Main(string[] args) { A a = new C(); // OK List<A> listOfA = new List<C>(); // compiler Error … Read more
I have an ArrayList, a Collection class of Java, as follows: ArrayList<String> animals = new ArrayList<String>(); animals.add(“bat”); animals.add(“owl”); animals.add(“bat”); animals.add(“bat”); As you can see, the animals ArrayList consists of 3 bat elements and one owl element. I was wondering if there is any API in the Collection framework that returns the number of bat occurrences … Read more
This question already has answers here: Sort ArrayList of custom Objects by property (29 answers) Closed 8 years ago. I have a class named Fruit. I am creating a list of this class and adding each fruit in the list. I want to sort this list based on the order of fruit name. public class … Read more
What is the best way to convert a JSON code as this: { “data” : { “field1” : “value1”, “field2” : “value2” } } in a Java Map in which one the keys are (field1, field2) and the values for those fields are (value1, value2). Any ideas? Should I use Json-lib for that? Or better … Read more
Is there a way that you can get a collection of all of the Models in your Rails app? Basically, can I do the likes of: – Models.each do |model| puts model.class.name end 29 Answers 29
Is it possible to show all collections and its contents in MongoDB? Is the only way to show one by one? 6 Answers 6
In Java we could do the following public class TempClass { List<Integer> myList = null; void doSomething() { myList = new ArrayList<>(); myList.add(10); myList.remove(10); } } But if we rewrite it to Kotlin directly as below class TempClass { var myList: List<Int>? = null fun doSomething() { myList = ArrayList<Int>() myList!!.add(10) myList!!.remove(10) } } I … Read more
I want to have a reversed list view on a list (in a similar way than List#sublist provides a sublist view on a list). Is there some function which provides this functionality? I don’t want to make any sort of copy of the list nor modify the list. It would be enough if I could … Read more
