help me

[jone wiilum]

public static Iterator reverse(List list) {
Collections.reverse(list);
return list.iterator();
}
public static void main(String[] args) {
List list = new ArrayList();
list.add("1"); list.add("2"); list.add("3");
for (Object obj: reverse(list))
System.out.print(obj + ", ");
}
What is the result?

result is Compilation fails. how?

[Abdullah Mamun]

The problem is you are returning Iterator object from reverse() method. To the for-each loop you have to provide collection, which in this case List.

[dhwani mathur]

Hi Al Mamun

Please can you explain the above concept in detail
bcoz i am not getting what actualy is being returned?
and why we
cant traverse in a reverse order ?although we are
inserting some elements in List...........
It will be kinda of you ................


Thanks in advance............

[Andrew Han]

foreach syntax:
for(variable:collection)

works for Collections and arrays

[Abdullah Mamun]

Hi Dhwani

Originally posted by jone wiilum:
public static Iterator reverse(List list) {
Collections.reverse(list);
return list.iterator();
}

Look at the bold lines in the above code. The return type is Iterator which is using to traverse the list, but for-each construct only allows collection or array.

Originally posted by dhwani mathur:
...why we cant traverse in a reverse order ?...

There is no problem regarding traverse in a reverse order in this example.
[ August 23, 2007: Message edited by: Al Mamun ]

[dhwani mathur]

Hi Al Mamun!!


Thanks for your explanation
now i am clear with the concept.....



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