In this post under Java, I will explain with example the purpose of Collections “checkedCollection” method. From Java 5 onwards, we started using Generics to ensure compile time type safety. As a result of which we were unable to add element of one data type to collections of elements of another data type. At compile…… Continue reading Collections checkedCollection example

In this post under Java Core, I will explain with example the pupose of Collections’ “indexOfSubList” method. Lets say they are two lists list1 and list2. “indexOfSubList” will search in list1 for position from where the elements of “list2” are repeated in “list1”. Once the position is found it is returned as index. In other…… Continue reading Collections indexOfSubList method

In this post under Java Collections, I will explain with example the purpose of Collections “replaceAll” method. This method replaces all occurrences of a particular element with its replacements. This method can be used only with “List” data structure. Below is the main class showing an example Main class 1 package core.collection; 2 3 import…… Continue reading Collections replaceAll method

In this post under Java Collections, I will explain with example the purpose of “Comparable” interface. Before we understand “Comparable” interface we need to understand the difference between “ordered” and “sorted” collections. In Ordered collections, elements are placed in a collection according to insertion order or according to some order and the order is not…… Continue reading Java Comparable interface

In this post under Java, I will show with example the purpose of static “addAll” method in “Collections” class. The “addAll” method populates a collection with the given list of elements. This method takes two arguments1) the collection that it has to fill or populate2) variable length arument that will contain the elements that has…… Continue reading Populating collection with multiple elements in one single method call

In this post under Java, I will show with example the purpose of “frequency” static method in “Collections” class. The “frequency” method returns the number of times an element is repeated in a collection. This method takes two argument1) the collection it has to search2) the element for which it has to return the frequency.…… Continue reading Collections frequency method

In this post under Java Collections, I will show with example how to randomly shuffle elements of a list. Below is the complete code for your reference. Main class 1 package core.collection; 2 3 import java.util.ArrayList; 4 import java.util.Collections; 5 import java.util.List; 6 7 public class ShuffleListDemo { 8 public static void main(String[] args) {…… Continue reading Shuffling elements of a list

In this post under Java Collections, I will explain with example how to swap elements of an list. Below is the complete main code for your reference. Main class 1 package core.collection; 2 3 import java.util.ArrayList; 4 import java.util.Collections; 5 import java.util.List; 6 7 public class SwappingListDemo { 8 public static void main(String[] args) {…… Continue reading Swapping elements of a list

In this post under Java Collections, I will show with example how to reverse the elements order in a list. Below is the complete code for your reference. Main class 1 package core.collection; 2 3 import java.util.ArrayList; 4 import java.util.Collections; 5 import java.util.List; 6 7 public class ReverseListDemo { 8 public static void main(String args[])…… Continue reading Reverse the order of elements in the list