How to loop over ArrayList in Java

Iterate an ArrayList in Java is done by using three loops:

• The for loop
• The while loop or do..while
• The while+iterator loop

The example below show how to use the three methods mentioned.

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

public class main{

 public static void main(String[] args) {
  
  ArrayList arraylist = new ArrayList();

  arraylist .add(1);
  arraylist .add(2);
  arraylist .add(3);
  
  System.out.println("for loop");
  for(int i = 0 ; i < arraylist .size(); i++)
   System.out.println(arraylist .get(i));
  
  System.out.println("Advanced for loop");
  for(Integer n : arraylist)
   System.out.println(n);
  
  System.out.println("while+iterator loop");
  int i = 0;
  while(i iterator = arraylist.iterator();
  while(iterator.hasNext())
   System.out.println(iterator.next());
 }
}

Compilation and execution:

for loop
1
2
3

Advanced for loop
1
2
3

while+iterator loop
1
2
3

How to browse an ArrayList using the Enumeration interface

import java.util.ArrayList;
import java.util.Collections;
import java.util.Enumeration;

public class main{

  public static void main(String[] args) {
  
     ArrayList alist = new ArrayList();

     alist.add("a");
     alist.add("b");
     alist.add("c");

     // get Enumeratioin object
     Enumeration enumeration = Collections.enumeration(alist);
  
     // iterate
     while(enumeration.hasMoreElements())
        System.out.println(enumeration.nextElement());
  }
}

After compilation and execution of this code:

a
b
c