Appropriate Assertion

[Aniket Patil]

  
 
public class AssertDemo
{
   public static Boolean message()
   {
      System.out.println("Error!!");
      return false;
   }
 
   public static void main(String[] args)
   {
      boolean b = false;
      assert b:message();
   }
}

Is the above an appropriate use of assertions? Acc. to Whizlabs it is, but for me, a method is getting called which wouldn't be if assertions were disabled (the side-effect thing).

Or, is Whizlabs correct, only because the method does nothing "significant"?
[ October 07, 2006: Message edited by: Aniket Patil ]

[Barry Gaunt]

The method is only called if assertions are enabled and an AssertionError is thrown. I think that we are meant to assume that the purpose of the message() method is just to produce an appropriate message for the AssertionError. It's hard to decide if it's good or bad in my opinion.

What is tabu is to call a method which changes the computational state of the program as part of the asserted clause (left of the colon).
[ October 07, 2006: Message edited by: Barry Gaunt ]

[Santhosh Raje]

Hi Ankit,
You are right that "Assertions are disabled by default" .
So During runtime of the code if they are not enabled then there wont be any output.
If assertions are enabled then the output will be an Assertion Error.

[Petrus Pelser]

Even though this assert statement calls a method, it does not have any side effects - the method does not change the state of the class. All the variable values stay the same.