Collection : ArrayList Example

This tutorial contains description of Collection ArrayList with example.


 

Ads

Tutorials   
How to read properties file in Java? Generate random numbers in Java Cloneable Interface in Java What is the flaw with the Stack class? List In Java Java Stack Example HashSet In Java Enumeration in java How to generate random number in java Iterator in java Queue in java Transient Java Keyword clone method in Java Java Queue example Logger in Java Java current date - How to get current date in Java Collection : LinkedList Example Collection : ArrayList Example Random alpha numeric string of fixed size Java List Iterator Example The Hashtable Class The BitSet class Java Vector Java Enumeration Data Structures in Java Java Transient Variable Java Date Format Example Java Properties File Example Map.Entry Java Interface Java Property File java preferences,Change the value of Preferences by user Retrieving a Preference Node Java hasNext Write Keys and Values to the Properties file in Java Get All Keys and Values of the Properties files in Java Properties file in Java Properties file in Java Determining If a Preference Node Contains a Specific Value Change the value of Preferences by user Clone method example in Java Implementing a Simple Event Notifier Determining When a Preference Node Is Added or Removed Listening for Changes to Preference Values in a Preference Node Importing Preferences Finding a Preference in a Preference Tree Retrieving the Parent and Child Nodes of a Preference Node Determining If a Preference Node Exists Removing a Preference Node Creating a Preference Node Getting the Maximum Size of a Preference Key and Value
Ads

Collection : ArrayList Example

This tutorial contains description of Collection ArrayList with example.

ArrayList :

For ArrayList<E> import java.utill.ArrayList. It provides expandable arrays that is it supports dynamic array.
It can automatically grow when you add new element and it shrink when you delete any element.
Size of standard arrays are fixed which is defined at the time of array creation, which cause problem when
you don't know the number of elements to add. For such condition, the Collection Framework provides ArrayList which can be dynamically increase or decrease in length.

Some method of ArrayList -

add(Object o) - It adds the specified element at the end of the list.
add(int index,Object element) - By using this method you can add specified element the specified position in ArrayList.
remove(int index) - Removes the element at the specified index from the Arraylist.

Example :

package collection;

import java.util.ArrayList;

class ArrayListExample {
public static void main(String[] args) {
// Creating ArrayList of Integer
ArrayList<Integer> list = new ArrayList<Integer>();
int size;
size = list.size();
System.out.println("Initial size of ArrayList : " + size);

// Adding elements in ArrayList
list.add(333);
list.add(400);
list.add(200);
list.add(1, 999);

size = list.size();
System.out.println("Size of ArrayList after adding elements : " + size);
System.out.println("Elements of ArrayList : ");
for (int i = 0; i < size; i++) {
System.out.println(list.get(i));
}

// Removing element from ArrayList
list.remove(3);
size = list.size();
System.out.println("Size of ArrayList after removing elements : "
+ size);
System.out.println("Elements of ArrayList : ");
for (int i = 0; i < size; i++) {
System.out.println(list.get(i));
}
}
}

Description : In this example we are creating ArrayList and using its some methods. We are creating ArrayList list for Integers as -
ArrayList<Integer> list = new ArrayList<Integer>();
size()
method returns size of the list. Initially size of ArrayList is zero. It means list has no element. Next by calling add() method we can add any number of elements. We can print list elements by get() method ,using for loop.
For removing element from list we can call remove() mehod.

Output :

Initial size of ArrayList : 0
Size of ArrayList after adding elements : 4
Elements of ArrayList : 
333
999
400
200
Size of ArrayList after removing elements : 3
Elements of ArrayList : 
333
999
400

Advertisements

Ads
Share on Google+Share on Google+

Collection : ArrayList Example

Posted on: September 7, 2012 If you enjoyed this post then why not add us on Google+? Add us to your Circles

Advertisements

 

Discuss: Collection : ArrayList Example  

Post your Comment


Your Name (*) :
Your Email :
Subject (*):
Your Comment (*):
  Reload Image
 
 
Comments:0

Ads

 

Ads