I m new to Java Collections and my doubt is why can't i traverse a element in linkedlist in backward directions.Below I'll explain what i did and please clarify my doubts.
Can't i use iterator and listiterator interface in the same program to traverse a set of elements in forward and backward iterations ?
Code Snippet :
import java.util.*;
class NewClass{
public static void main(String args[]){
LinkedList<String> obj = new LinkedList<String>();
obj.add("vino");
obj.add("ajith");
obj.add("praveen");
obj.add("naveen");
System.out.println(obj);
System.out.println("For loop ");
//using for loop
for(int count=0; count < obj.size(); count++){
System.out.println(obj.get(count));
}
System.out.println("For each loop ");
//using foreach loop
for(String s:obj){
System.out.println(s);
}
System.out.println("Whileloop ");
//using whileloop
int count=0;
while(obj.size() > count){
System.out.println(obj.get(count));
count++;
}
System.out.println("Forward Iterations ");
//using iterator
Iterator it = obj.iterator();
while(it.hasNext()){
System.out.println(it.next());
}
ListIterator lit = obj.listIterator();
System.out.println("Backward Iterations");
while(lit.hasPrevious()){
System.out.println(lit.previous());
}
}
}
Output
[vino, ajith, praveen, naveen]
For loop
vino
ajith
praveen
naveen
For each loop
vino
ajith
praveen
naveen
Whileloop
vino
ajith
praveen
naveen
Forward Iterations
vino
ajith
praveen
naveen
Backward Iterations
Where is the output for Backward Iterations? Please anyone help me.Thanks in advance
I think you want a descendingIterator
.
Iterator lit = obj.descendingIterator();
System.out.println("Backward Iterations");
while(lit.hasNext()){
System.out.println(lit.next());
}