Thread: error in HashSet

Hi,

I have a small program here where in im learning to use HashMap.

import java.util.HashSet;
import java.util.Set;
 
public class test {
 
        public static void main(String[] args) {
                Set set = new HashSet();
                set.add("pooja");
                if(set.contains("pooja")) {
                        System.out.println("contains"); }
                else {
                        System.out.println("does not contain"); }
        }
}

But when i try to run this, it gives me an error saying
"Note: test.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details."

Can anyone tell me what does this error mean ? and what do i do to make this program run ??

Thank you in advance ..