Help Me Downcast

[Amit Batra]

 
import java.util.*;
import java.io.*;
 
class Vct
{
public static void main(String...arg){
Vector<String>aList=new Vector<String>();
aList.add("Blah");
aList.add("Blah blah");
aList.add("null");
    List<? extends Object>l=aList;
 
for(Object s:l)
System.out.println(s);
}
}; 

The above works fine. Now if I wish to change the for loop just a bit like:
for(String s String)l)
System.out.println(s);
It doesnt work. The problem is in the for loop How can I downcast the List's values which are Objects to Strings to get my proposed for loop to work?

[Naseem Khan]

One option is cast o in for loop like this...

for(Object o: l){
  String s=(String)o;
  System.out.println(s);
}

or you can directly assign aList in generic type List<? extends String> instead of List<? extends Object>. In that case, your for loop will change to...

for(String s:l){}

Naseem

[Amit Batra]

Thanks Naseem. I was trying to cast in the for each loop itself but I guess thats just not a possibillity and must be done in the body of the loop.

[Ramamoorthy Periasamy]

may be you can use List<? extends String> l = aList;
instead of List<? extends Object> l = aList;

 import java.util.*;
 
public class Vct { 
public static void main(String...arg) {
Vector<String>aList=new Vector<String>();
aList.add("Blah");
aList.add("Blah blah");
aList.add("null");    
List<? extends String> l = aList;

for(String s:l)
System.out.println(s);
}
}