compilation error(version problem?)

[Ms.Ranjan]

hi i tried the following example

import java.util.*;

public class Program
{
    public static void main(String[] args)
    {
        // Create an ArrayList containing a simple sentence.
        ArrayList arrList = new ArrayList();
        arrList.add(new String("Today"));
        arrList.add(new String("is"));
        arrList.add(new String("Thursday"));

        // Change the day to Friday.
        arrList.set(2, new String("Friday"));

        Iterator iter = arrList.iterator();
        while (iter.hasNext())
        {
            System.out.print(iter.next() + " ");
        }
    }
}

i get this following compilation error

C:\world>javac Program.java
Note: Program.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.

i use jdk1.5.0_15 is this the problem? i think the problem is using .add() method ...am i wrong?

[Nicholas Jordan]

i use jdk1.5.0_15 is this the problem? i think the problem is using .add() method ...am i wrong?

C:\world>javac Program.java
Note: Program.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.

Google for Java Generics.

TreeMap<Integer,Object> tm = new TreeMap<Integer,Object>();

Or something like that.

[Norm]

Recompile with -Xlint:unchecked for details.

Have you tried what the compiler recommends? You will get more detailed line-by-line warnings showing where the problems are in your code.
To remove these warnings, you need to use Generics. They allow the compiler to type check your use of methods that previously took type Object and required the programmer to typecast objects passed into and out of Collection items for example. By using Generics, you won't have to type cast and the compiler will check that your objects are the correct type.

[Ms.Ranjan]

Thankyou very much i could solve it by using this...

ArrayList<String> arrList = new ArrayList<String>();