About Question com.enthuware.scja.v1.2.11 :

[TheSarjo]

Hello and thank you for your support!

i'd like to discuss about this question, that i don't understand fully (although i've answered right.. ).

the question is:

A JavaBean has a property named size, which is accessible to and modifiable by all other classes. Which of the following statements are correct regarding this class?

one of the wrong answer was:
the class must have an instance variable named size.
and the explanation given is:
While quite intuitive and common, this is not a necessity. The getter and setter methods may have some computational logic that does not involve any instances variable or may involve multiple instance variables. If a JavaBean has a getX and setX method, it is said to have a property x, irrespective of whether it has an instance variable x or not.

i don't understand... shouldn't there be a variable named size to have the setter and getter setSize and getSize?
otherwise the setter and getter would get different names, i guess... so kindly, can you help me?
best regards

[admin]

Yes, for example, class Shape could have a getArea method but no area field because it is computed on the fly. So 'area' would still be a valid property (although read only, in this case) from JavaBeans perspective.

HTH,
Paul.

[TheSarjo]

Hi Paul,

thank you for your reply, but still, i've not understood, can you make me a practical example?

by the way... i wanted to thank all the staff in enthuware, i've passed the exam, and your software has been helpful!

[admin]

The one I gave is a practical example:

Code: Select all

class Shape{
 abstract double getArea();
}

class Square extends Shape{
 private int side;
 public int getArea(){ return side*side; }
}

HTH,
Paul.