What is Java List and List Iterator?

Learning Java Programming Made Easy

List And List Iterator

Java List Interface:

List Interface is the subinterface of Collection.It contains methods to insert and delete elements in index basis.It is a factory of ListIterator interface.

Java List Example

1. import java.util.*;  
2. public class ListExample{  
3. public static void main(String args[]){  
4. ArrayList<String> al=new ArrayList<String>();  
5. al.add("Amit");  
6. al.add("Vijay");  
7. al.add("Kumar");  
8. al.add(1,"Sachin");  
9. System.out.println("Element at 2nd position: "+al.get(2));  
10. for(String s:al){  
11.  System.out.println(s);  
12. }  
13. }  
14. }

Java ListIterator Interface:

ListIterator Interface is used to traverse the element in backward and forward direction.

Example of ListIterator Interface

1. import java.util.*;  
2. public class TestCollection8{  
3. public static void main(String args[]){  
4. ArrayList<String> al=new ArrayList<String>();  
5. al.add("Amit");  
6. al.add("Vijay");  
7. al.add("Kumar");  
8. al.add(1,"Sachin");  
9. System.out.println("element at 2nd position: "+al.get(2));  
10. ListIterator<String> itr=al.listIterator();  
11. System.out.println("traversing elements in forward direction...");  
12. while(itr.hasNext()){  
13. System.out.println(itr.next());  
14. }  
15. System.out.println("traversing elements in backward direction...");  
16. while(itr.hasPrevious()){  
17. System.out.println(itr.previous());  
18. }  
19. }  
20. }