How to convert Set containing values ​​in string

public static void main(String[] args) { // TODO Auto-generated method stub String str = "abcdaa"; dups(str); } public static void dups(String str){ HashSet hs = new HashSet(); char[] ch = str.toCharArray(); for(int i=0; i < ch.length;i++){ h

Type erasure in the confusion of generics

I was reading concept of type erasure in generics. While executing the below piece of code I got confused. public class CollectionsWild { void Test(Collection<?> t){ System.out.println("Collection"); } void Test(List<Integer> t){ Sys

Is there a utility to get a subset of Laravel Collection?

Is there any method like only for collections? $col=collection(['foo'=>'x','bar'=>'z',-]); $subcol=$col->only(['foo','bar']); // returns ['foo'=>'x','bar'=>'z'] I know that I can use the following function to achieve that, but I hope there

How comparable and comparator work in collections?

This code is from the famous Java SCJP6 book. I can't understand the difference between title and d.getTitle() in the compareTo method. How are both title and d.getTitle() getting and comparing values? class DVDInfo implements Comparable<DVDInfo> {

Iterator of the object []

Is there a way to obtain the iterator of an array? Something like that: class MyCollection implements Iterable<String> { String[] items; @Override public Iterator<String> iterator() { return items.iterator(); //obviously, it doesn't compile. }

Iterate through a collection

I am trying to create hasnext() has next() methods for a iterator so that the output of a collection will be: "printing","elements","in","order","from","collection" input: [A] - ["printing&q

Gradle, set a collection of properties

I'm working in a Gradle Script in order to deploy three Android environment automatically. The idea is define a group of properties whose will be used to hold all data from each environment. Example [DEV, QA & Live] { buildFolder ="..." envN

C #: alternative to exists or getfirstordefault

I have a class class Person { int Age; string Name; } List<Person> pList = new List<Person>(); pList.Exists(p=> p.Name == "testName"); <-- need an alternative for this. I'm using .net 3.0. As such I don't have access to getFirs

add items from the list to the string array

I have a String array like, String[] abc= new String[]{}; and my List has some values. I iterate the list and add each list element to string array. for(int i=0; i<errList.size(); i++) { abc[i] = errList.get(i).getSrceCd(); } errList.size() has 6 val

Access to type-specific methods & ldquo; class, in a collection

Situation: I have an abstract class with several methods: I have a few sub classes that extend the class above I have a collection <MyAbstractClass> collection filled with new objects of the sub classes in my main class I have a unique method of one

Prerequisite for TreeMap

Like for a object to be inserted into a HashMap the object should implement the equals() and the hashcode() method(not necessarily). Are there any special conditions for an object to be inserted in a TreeMap ?Unless a Comparator which mutually compar

Which C # data structure should I use?

This question pertains to C#, LINQ grouping and Collections. I'm currently working on a grouping issue and I wanted to get some feedback from the community. I've encountered this particular problem enough times in the past that I'm thinking of writin

Problem with Maps in Java

I have a Hashmap which has X number of elements I need to move this map into another map This is what my code looks like Map originMap = initialize(); Map destMap = new Hashmap (); int originMapSize = originMap.size(); Set<Map.Entry<K, V>> ent

Java Collections Logic / Over encoding issue

Below is an implementation of an exercise I've been asked to do (see comments). It works, and the reason I'm posting it is that the function checkMiracle looks like it should be contained in a much smaller loop of code - I'm writing out the same thin

Periodically iterating on a constantly changing collection

I have a collection of objects that's constantly changing, and I want to display some information about the contents every so often (my application is multi-threaded, and differently threads are constantly submitting requests to modify an object in t

Reference copy of the Java collection

Is there a standard Java (1.5+) implementation (i.e. no 3rd party) of a collection which allows me to glue several collections into one? Here's a sketch, of how it works: final SomeCollection x = new SomeCollection(); final ArrayList a = new ArrayLis

Is a variable linked to a collection element possible?

I'm trying to bind to an item inside a collection but the index for that item needs to be "variable". Take the following pseudo syntax for example: <TextBlock Text="{Binding Fields[{Binding Pos}]}" /> Is something like this possi

Best practice: How to expose a ICollection read-only

I have an ICollection<T> called foos in my class which I want to expose as read-only (see this question). I see that the interface defines a property .IsReadOnly, which seems appropriate... My question is this: how do I make it obvious to the consum