How to iterate or traverse ArrayList in Java
There are many ways to traverse over ArrayList.For ex: simple for loop,for-each loop and Iterator.
Lets have a look at the implementation of all different ways of traversing ArrayList.
1: import java.util.ArrayList;
2: import java.util.Iterator;
3: /**
4: *
5: */
6: /**
7: * @author
8: *
9: */
10: public class ArrayListTraverseExample {
11: /**
12: * @param args
13: */
14: public static void main(String[] args) {
15: ArrayList<String> listCompanies = new ArrayList<String>();
16: listCompanies.add("Infosys");
17: listCompanies.add("TCS");
18: listCompanies.add("Cognizant");
19: listCompanies.add("Google");
20: System.out.println("Size of ArrayList : " + listCompanies.size());
21: System.out.println("\n*******Traversing ArrayList using for-each loop*******");
22: for(String company: listCompanies){
23: //print all elements from ArrayList one by one.
24: System.out.println("List of Companies are:"+company);
25: }
26: System.out.println("\n*******Traversing ArrayList using Iterator*******");
27: Iterator<String> itr = listCompanies.iterator();
28: while(itr.hasNext()){
29: System.out.println("List of Companies are:"+itr.next());
30: }
31: //You can also Loop over ArrayList using traditional for loop
32: System.out.println("\n*******Traversing ArrayList using simple for loop*******");
33: for(int i =0; i<listCompanies.size(); i++){
34: System.out.println("List of Companies are:"+listCompanies.get(i));
35: }
36: }
37: }
Output:
Size of ArrayList : 4
*******Traversing ArrayList using for-each loop*******
List of Companies are:Infosys
List of Companies are:TCS
List of Companies are:Cognizant
List of Companies are:Google
*******Traversing ArrayList using Iterator*******
List of Companies are:Infosys
List of Companies are:TCS
List of Companies are:Cognizant
List of Companies are:Google
*******Traversing ArrayList using simple for loop*******
List of Companies are:Infosys
List of Companies are:TCS
List of Companies are:Cognizant
List of Companies are:Google
Please go through the program properly.Enjoy Reading.
