Doubt in ExamLab question...

[Hareendra Reddy]

Hi all...

public class Studio{
     private int cust=0;
     private int color=40;

     /* More Methods */

     private Studio takePhoto(int numberOfCopies){
          assert numberOfCopies>=0:"Negative number of copies";
          cust++;
          int x=cust*2;
          assert x+6>=0:"Invalid ID number "+(x+6);
          color-=cust*2;
          assert cust!=6: "Invalid flag "+(cust=6);
          return new Studio();
     }

     /* More Methods */

     public void photoSequence(Studio... std){
          for(int i=0; i<std.length;i++){
               std[i].cust=12;
               assert std[i].cust>=20:"Invalid studio object";
          }
          makeColor0();
          assert color<=9:"Invisible color information";
     }

     /* More Methods */

     private native void makeColor0();
}

The question is number of appropriate uses of assertions...

explanation is saying that the following usage is inappropriate ..

 for(int i=0; i<std.length;i++){
               std[i].cust=12;
               assert std[i].cust>=20:"Invalid studio object";
          }

Here we are evaluating the argument passed to public method but we control the code that is cust value has been assigned 12,
so how this is considered as inappropriate??

Thanks

[Amir Ashfaq]

Your question has its answer.. as 12 is assigned within the code and you are sure about the value of "cust" after the execution of that line , so no need for assert "cust>=20".

As Assertion means your assumption, so why you will assume that the value will be >= 20, as you yourself has assigned it 12.


hope you understand...

[T Vergilio]

but it is not inappropriate, is it? You are assessing the value of a variable after you manipulated it, so it should be fine... I don't understand why it isn't either, Hareendra.