Array List Example in java
In this example we are going to show the use of java.util.ArrayList.
We will be creatiing an object of ArrayList class and performs various
operations like adding removing the objects.
Arraylist provides methods to manipulate the
size of the array that is used internally to store the list. ArrayList extends AbstractList and implements
List, Cloneable, Serializable.
ArrayList capacity .grows automatically. The ArrayList is not
synchronized. It permits
all elements including null.
In this program we are inserting a value. We are using
three methods of ArrayList class.
add(Object o): Appends the specified element to the end
of this list. It returns a boolean value.
size(): Returns the number of elements in this
list.
remove(int index): Removes the element at the specified
position in this list. It returns the element that was removed from the list. It
throws IndexOutOfBoundsException : if index is out of range.
Code of a program is given below:
import java.util.*;
public class ArrayListDemo{
public static void main(String[] args) {
ArrayList<Object> arl=new ArrayList<Object>();
Integer i1=new Integer(10);
Integer i2=new Integer(20);
Integer i3=new Integer(30);
Integer i4=new Integer(40);
String s1="tapan";
System.out.println("The content of arraylist is: " + arl);
System.out.println("The size of an arraylist is: " + arl.size());
arl.add(i1);
arl.add(i2);
arl.add(s1);
System.out.println("The content of arraylist is: " + arl);
System.out.println("The size of an arraylist is: " + arl.size());
arl.add(i1);
arl.add(i2);
arl.add(i3);
arl.add(i4);
Integer i5=new Integer(50);
arl.add(i5);
System.out.println("The content of arraylist is: " + arl);
System.out.println("The size of an arraylist is: " + arl.size());
arl.remove(3);
Object a=arl.clone();
System.out.println("The clone is: " + a);
System.out.println("The content of arraylist is: " + arl);
System.out.println("The size of an arraylist is: " + arl.size());
}
}
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The output of program will be like this:
C:\Java Tutorial>javac ArrayListDemo.java
C:\Java Tutorial>java ArrayListDemo
The content of arraylist is: []
The size of an arraylist is: 0
The content of arraylist is: [10, 20, tapan]
The size of an arraylist is: 3
The content of arraylist is: [10, 20, tapan, 10, 20, 30, 40, 50]
The size of an arraylist is: 8
The clone is: [10, 20, tapan, 20, 30, 40, 50]
The content of arraylist is: [10, 20, tapan, 20, 30, 40, 50]
The size of an arraylist is: 7
C:\Java Tutorial> |
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