Android ArrayList forEach

Earlier we shared ArrayList example and how to initialize ArrayList in Java. In this post we are sharing how to iterate (loop) ArrayList in Java.

There are four ways to loop ArrayList:

1. For Loop
2. Advanced for loop
3. While Loop
4. Iterator

Lets have a look at the below example I have used all of the mentioned methods for iterating list.

import java.util.*; public class LoopExample { public static void main(String[] args) { ArrayList arrlist = new ArrayList(); arrlist.add(14); arrlist.add(7); arrlist.add(39); arrlist.add(40); /* For Loop for iterating ArrayList */ System.out.println("For Loop"); for (int counter = 0; counter < arrlist.size(); counter++) { System.out.println(arrlist.get(counter)); } /* Advanced For Loop*/ System.out.println("Advanced For Loop"); for (Integer num : arrlist) { System.out.println(num); } /* While Loop for iterating ArrayList*/ System.out.println("While Loop"); int count = 0; while (arrlist.size() > count) { System.out.println(arrlist.get(count)); count++; } /*Looping Array List using Iterator*/ System.out.println("Iterator"); Iterator iter = arrlist.iterator(); while (iter.hasNext()) { System.out.println(iter.next()); } } }

Output:

For Loop 14 7 39 40 Advanced For Loop 14 7 39 40 While Loop 14 7 39 40 Iterator 14 7 39 40

In the comment section below, Govardhan asked a question: He asked, how to iterate an ArrayList using Enumeration. Govardhan here is the code:

How to iterate arraylist elements using Enumeration interface

import java.util.Enumeration; import java.util.ArrayList; import java.util.Collections; public class EnumExample { public static void main(String[] args) { //create an ArrayList object ArrayList arrayList = new ArrayList(); //Add elements to ArrayList arrayList.add("C"); arrayList.add("C++"); arrayList.add("Java"); arrayList.add("DotNet"); arrayList.add("Perl"); // Get the Enumeration object Enumeration e = Collections.enumeration(arrayList); // Enumerate through the ArrayList elements System.out.println("ArrayList elements: "); while(e.hasMoreElements()) System.out.println(e.nextElement()); } }

Output:

ArrayList elements: C C++ Java DotNet Perl