JAVA EE: Java : Collection Framework : ArrayList (Foreach and Iterator)

Wednesday 1 October 2014

Java : Collection Framework : ArrayList (Foreach and Iterator)

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ArrayListExample.java

import java.util.ArrayList;
import java.util.List;

public class ArrayListExample
{

    public static void main(String[] args)
    {
        List<String> list = new ArrayList<String>();

        list.add("Ram");
        list.add("Dave");
        list.add("Peter");
        list.add("John");

        System.out.println(list);
    }

}

Output

[Ram, Dave, Peter, John]

ArrayListForEachExample.java

import java.util.ArrayList;
import java.util.List;

public class ArrayListForEachExample
{

    public static void main( String[] args )
    {
        List<String> list = new ArrayList<String>();

        list.add("Ram");
        list.add("Dave");
        list.add("Peter");
        list.add("John");

        /*
         * Using for-each loop getting each element from the list.
         */

        for( String name : list )
        {
            System.out.println(name);
        }

    }

}

Ouput

Ram
Dave
Peter
John

ArrayListForLoopIteratorExample.java

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

public class ArrayListForLoopIteratorExample
{

    public static void main( String[] args )
    {
        List<String> list = new ArrayList<String>();

        list.add("Ram");
        list.add("Dave");
        list.add("Peter");
        list.add("John");

        /*
         * Using Iterator to get each element from the list.
         */

        for( Iterator<String> iterator = list.iterator(); iterator.hasNext(); )
        {
            String name = iterator.next();
            System.out.println(name);
        }

    }

}

Output

Ram
Dave
Peter
John

ArrayListWhileLoopIteratorExample.java

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

public class ArrayListWhileLoopIteratorExample
{

    public static void main( String[] args )
    {
        List<String> list = new ArrayList<String>();

        list.add("Ram");
        list.add("Dave");
        list.add("Peter");
        list.add("John");

        Iterator<String> iterator = list.iterator();

        /*
         * Using Iterator to get each element from the list.
         */
        while( iterator.hasNext() )
        {
            String name = iterator.next();
            System.out.println(name);
        }

    }

}