warning [unchecked] unchecked call to add() in ArrayList

[Graham Cole]

I get a warning such as the one in the subject line of this post whenever I call things like .add() or .put() (depending on the type of variable of course). I'm wondering what a "checked" call would look like so that I can ensure the stability of my program and get the compiler to quit warning me about me ramped disregard for checking calls.

[marc weber]

The warning is about the "type safety" introduced by generics in Java 1.5. To eliminate the warnings, you can specify the type of object that the ArrayList is supposed to hold -- for example, ArrayList<String>...

import java.util.*;
 
class Warnings {
  public static void main(String[] args) {
    String str = "ABC";
 
    //no type specified -- generates warning...
    ArrayList noGenList = new ArrayList();
    noGenList.add(str);
 
    //type specified -- no warning...
    ArrayList<String> genList = new ArrayList<String>();
    genList.add(str);
  }
}

[ October 06, 2005: Message edited by: marc weber ]

[Layne Lund]

As you can see, the method call itself does not change. You need to change the declaration of your ArrayList variable instead. If you want more information about this, google for "Java generics".

Layne