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.

Commonly used methods of List Interface:

1. public void add(int index,Object element);
2. public boolean addAll(int index,Collection c);
3. public object get(int Index position);
4. public object set(int index,Object element);
5. public object remove(int index);
6. public ListIterator listIterator();
7. public ListIterator listIterator(int i);

class Testc1

{

public static void main(String gh[])

{

ArrayList al1=new ArrayList();

al1.add("Ram");

al1.add("Shyam");

al1.add("Krishan");

List li=al1.subList(0,3);

Object o=li.get(2);

System.out.println(o);

}

}

Set method

class Testc1

{

public static void main(String gh[])

{

ArrayList al1=new ArrayList();

al1.add("Ram");

al1.add("Shyam");

al1.add("Krishan");

List li=al1.subList(0,3);

//Object o=li.get(2);

System.out.println(li.set(1,"Hari"));

System.out.println(li);

System.out.println(al1);

}

}

---

Java ListIterator Interface

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

Commonly used methods of ListIterator Interface:

1. public boolean hasNext();
2. public Object next();
3. public boolean hasPrevious();
4. public Object previous();

Example of ListIterator Interface:

1.    import java.util.*;  

2.    public class TestCollection8{  

3.    public static void main(String args[]){  

4.      

5.    ArrayList<String> al=new ArrayList<String>();  

6.    al.add("Amit");  

7.    al.add("Vijay");  

8.    al.add("Kumar");  

9.    al.add(1,"Sachin");  

10.   

11. System.out.println("element at 2nd position: "+al.get(2));  

12.   

13. ListIterator<String> itr=al.listIterator();  

14.   

15. System.out.println("traversing elements in forward direction...");  

16. while(itr.hasNext()){  

17. System.out.println(itr.next());  

18.  }  

19.   

20.   

21. System.out.println("traversing elements in backward direction...");  

22. while(itr.hasPrevious()){  

23. System.out.println(itr.previous());  

24.  }  

25. }  

26. }  

Output:element at 2nd position: Vijay

       traversing elements in forward direction...

       Amit

       Sachin

       Vijay

       Kumar

       traversing elements in backward direction...

       Kumar

       Vijay

       Sachin

       Amit