Iterate a List in Java

This tutorial demonstrates the use of ArrayList, Iterator and a List. There are many ways to iterate a list of objects in Java. This sample program shows you the different ways of iterating through a list in Java.

In java a list object can be iterated in following ways:

Using Iterator class
With the help of for loop
With the help of while loop
Java 5 for-each loop
Following example code shows how to iterate a list object:

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import java.util.Iterator; import java.util.List; import java.util.ArrayList; public class IterateAList { public static void main(String[] argv) { ArrayList arrJavaTechnologies = new ArrayList(); arrJavaTechnologies.add("JSP"); arrJavaTechnologies.add("Servlets"); arrJavaTechnologies.add("EJB"); arrJavaTechnologies.add("JDBC"); arrJavaTechnologies.add("JPA"); arrJavaTechnologies.add("JSF"); // Iterate with the help of Iterator class System.out.println("Iterating with the help of Iterator class"); Iterator iterator = arrJavaTechnologies.iterator(); while (iterator.hasNext()) { System.out.println(iterator.next()); } // Iterate with the help of for loop System.out.println("Iterating with the help of for loop"); for (int i = 0; i < arrJavaTechnologies.size(); i++) { System.out.println(arrJavaTechnologies.get(i)); } // Iterate with the help of while loop System.out.println("Iterating with the help of while loop"); int j = 0; while (j < arrJavaTechnologies.size()) { System.out.println(arrJavaTechnologies.get(j)); j++; } // Iterate with the help of java 5 for-each loop System.out.println("Iterate with the help of java 5 for-each loop"); for (String element : arrJavaTechnologies) // or sArray { System.out.println(element); } } }