Encapsulation (computer programming): Difference between revisions

Revision as of 00:32, 24 February 2012

Revision as of 08:19, 27 February 2012

Line 24:

Position class:

With a growing awareness of the wireless Internet's vast potential, many pundits expect ___location-based services to provide opportunity for the first wireless killer app. For this article's sample code, I've chosen a class representing the geographical ___location of a point on the earth's surface. As a ___domain entity, the class, named Position, represents Global Position System (GPS) information. A first cut at the class looks as simple as:

public class Position

{

{

public double latitude;

public double longitudelatitude;

public double latitudelongitude;

}

}

The class contains two data items: GPS latitude and longitude. At present, Position is nothing more than a small bag of data. Nonetheless, Position is a class, and Position objects may be instantiated using the class. To utilize those objects, class PositionUtility contains methods for calculating the distance and heading -- that is, direction -- between specified Position objects:

public class PositionUtility

{

public static double distance( Position position1, Position position2 )

{

// Calculate and return the distance between the specified positions.

}

public static double heading( Position position1, Position position2 )

{

//public Calculatestatic anddouble returndistance( the heading fromPosition position1, toPosition position2. )

{

// Calculate and return the distance between the specified positions.

}

public static double distanceheading( Position position1, Position position2 )

{

// Calculate and return the heading from position1 to position2.

}

}

}

== General Definition ==