Collection Framework in Java,The Java collections framework (JCF) is a set of classes and interfaces that implement commonly reusable collection data structures.
Removing Duplicates Array Java Summary: Java is so developed by Designers to write code easily for Developers. Forget the laborious days of C/C++ coding. This tutorial "Removing Duplicates Array Java" is the place to prove it. It is a general and interesting code for beginners and this can be achieved in many ways in Java. …
It is a general and interesting code for beginners and this can be achieved in many ways in Java. This code, I would like to keep the code as simple as possible without using any methods and without using any laborious loops of C/C++. Here, I use only constructors but for adding elements to Vector …
It is a general and interesting code for beginners and this can be achieved in many ways in Java. This code, I would like to keep the code as simple as possible without using any methods and without using any laborious loops of C/C++. Here, I use only constructors but for adding elements to ArrayList …
WeakHashMap Example Java Tutorial HashMap hm1 = new HashMap(); If hm1 is not used in the remaining part of the code, that is not referenced, the hm1 object is eligibile for garbage collection. That is, as long as hm1 is referenced (this is known as reference to hm1 and I call particulary here as strong …
Sometimes, a data structure is preferred rather than an array in that data structure is growable and accepts dissimilar elements. Being growable dynamically, Vector is preferred when the number of elements to be added are not known earlier in advance or required to change the number of elements (modify the size). Vector is the generally …
Java Made Simple: What is Vector Java with Example? Read More »
Java Map Interface Tutorial Properties of Java Map Interface The Map interface stores the elements in key/value pairs (as in Hashtable). It does not accept duplicate keys. One key represents only one value. Two keys may have the same value. For example, two students, with roll numbers 35 and 46, may have the same marks …
Being a sub interface of Collection inteface, List Interface utilizes all the methods of Collection interface. List Interface accepts duplicate elements. List interface comes with operations like: To manipulate elements by their numerical position in the list with the methods such as remove(), set(), add(), addAll() and get(). To retrieve the numerical index number of …
for loop is used to iterate any data in Java as in most of the languages. To make the iteration of elements easier, the general for loop can be replaced with a new loop known as foreach Java loop in JDK 1.5. But this new foreach Java loop should be used only in arrays and …
Three most used implementations of Set interface are HashSet, TreeSet and LinkedHashSet. For a novice, it looks difficult to understand. When a list of differences is presented all at a single place, it is easier to understand. Start reading HashSet vs TreeSet Programs are available at HashSet Tutorial and TreeSet Tutorial. First let us see …
You must be very strong in Java DS to write comparisons between various Collection classes. This tutorial gives you possible Java DS comparisons. Enumeration vs Iterator Iterator vs ListIterator Vector vs ArrayList Array vs ArrayList for vs foreach Hashtable vs HashMap Set vs HashSet Map vs HashMap HashMap vs TreeMap Comparable vs Comparator HashSet vs …
In Java, Data structures, known as collection classes or collections framework, is a big topic as it involves many many classes. Choosing a right data structure, in Java, requires good experience and once chosen, writing part, a novice can do. DS is simple in Java because of no pointers. In this tutorial list iterator is …
Given in simple terms with example codes in respective links. Start reading Differences between HashSet and HashMap. Both look something same but are very different in each respect. Following tables give you both differences and similarities. Two programs are given on HashSet and HashMap. Both belong to Collections framework. One difference of eye-catching is HashSet …
There comes two classes ArrayList and LinkedList to store objects. Internally, ArrayList stores elements as an array form and LinkedList stores elements in node form. Due to their internal style of storing the elements, they come with different performance heads depending the nature of action performed like addition and retrieval. Programs are available at ArrayList …
Here we use asList() method of class Arrays. Following is the method signature static List asList(T array): The method returns a List object with all the elements of the array. The list returned is fixed size. That is, you cannot add further elements to the list. Following example on "Array to List Java" with asList() …
Here, toArray() method of Collections interface is used. This method returns an Object array containing the elements of collection class. Example on on "List to Array Java" explains the usage of toArray() method to convert List to array. import java.util.*; public class ListConvertArray { public static void main(String args[]) { // CREATING LIST, ADDING ELEMENTS …
It may be required sometimes to remove common elements two lists Java. Following is the code. ArrayList al1 contains 10, 20 and 30 and ArrayList al2 contains 20, 30, and 50. It is required from al1 to remove 20 and 30 as they are also present in al2. After removal, al1 should print only 10. …
It may be required sometimes to extract the common elements of two lists in Java. Given in simple terms in this tutorial List Extract Common Elements Java. Following code on List Extract Common Elements Java illustrates. import java.util.*; public class CommonElements { public static void main(String args[]) { ArrayList al1 = new ArrayList(); ArrayList al2 …
After studying Hashtable vs HashMap and HashMap vs TreeMap, let us study the differences between Map and HashMap. These two are very much related as HashMap is a class derived from Map interface. As a derived class of Map, the HashMap attains the properties of Map. Important and the most frequently used derived classes of …
After knowing Hashtable vs HashMap, now let us see the comparison of HashMap with TreeMap. Basically both are derived from Map interface and meant to store key/value pairs. But TreeMap inherits one more interface SortedMap and for this reason it attains the property of returning the elements in sorting order by default (irrespective of the …
After studying Set, HashSet and TreeSet individually, let us summarize their differences. Now let us go with Set and HashSet. These two are very much related as HashSet is a class derived from Set interface. As a derived class of Set, the HashSet attains the properties of Set. Important and the most frequently used derived …
