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