Number converter (GAE application)

Release note:
- Number Translator/Converter
- Version: 1.0
- Link: http://numbertranslator.appspot.com/

jbohn.blogspot.com

Decoupling

Decoupling refers to careful controls that separate code modules from particular use cases, which increases code re-usability. A common use of decoupling is to polymorphically decouple the encapsulation (see bridge pattern and adapter pattern) – for example, using a method interface that an encapsulated object must satisfy, as opposed to using the object's class.

(wiki)

Getters and Setters in design data type

Normally when we create a class, we always define Getters and Setters for instance variables to read and write its values. But it does not follow spirit of OOP/encapsulation. Encapsulation is a mechanism of hiding implemation details which process data from user, so the client should tell an Object what to do rather than asking an object about its state and telling it how to do.

Example:

CoordinateObject a = new CoordinateObject(1.0, 2.0);
CoordinateObject b = new CoordinateObject(3.0, 4.0);

// violates spirit of encapsulation
CoordinateObject c = new CoordinateObject(0.0, 0.0);
c.setX(a.getX + b.getX);
c.setY(a.getY + b.getY);

// better design
CoordinateObject a = new CoordinateObject(1.0, 2.0);
CoordinateObject b = new CoordinateObject(3.0, 4.0);
CoordinateObject c = a.plus(b);

(jbohn.blogspot.com)

"Mad" Game! ;)

A  lite desktop version of  Freaking Math game

Link download