Il Äo PO WEEKNAPPLIGATIOM DEVELOPMENT u. Li APPLIED INTELLIGENCE OOP Goes Beyond the Commonsense Meaning of 'Object to the specific. For example, in designing which sends the same check aekesi the inventory object shown in the fig- message to all be Mel jp see Ĺža be ure, the top of the hierarchy might be The ability of objec | The behaviors for responding to the This is the sec- message depend on the values of the | zofe Âťlar object. a SJE | ch implement it ap- ond a on ob: AREA a prorainnira tech- the abstract object, "collection." It zj s ze iji s caled PovmoĹĄi Risi [tis za. en len d ligues are used to invoke the behaviors sponds to a number of messages, such propil he aspects of object-oriented pro olivno irino object. For example, the verifica- as "add an item" and return an item. Go mia thal strupilfjes complex code. new technology tion message to an order object would ltisa general-purpose programming To better understand polymorphism, that's changing invoke an order behavior that would construct that might have been ke let's look'at the inventory object One of the way pro- send a message to an inventory object predefined in the system or might iz NeREviGes'ehecko ali ventogy (OE grammers and reguesting the guantity on hand for the Serie se . programmer's library of reus- nore might oda ole IC A sem Es ime lotne jesta to z The programmer implementing the in- simple to ee a OB Serene? Ke [ VSA NINI ORAL eRE guantity on hand. ventory: object lerarchy might define â Cece MEH TRE VNJ. of the term "ob- The benefit of this approach is in- categories of parts (such as Type A ho book liko tis PER ject," we have an creasingly important as systems get part, Type B part, and so on) as a sub- lie aa intuitive grasp of large and complex. Programmers imple- class of the collection because the inven: ; ol z ejena what that menting the order object do not need'to tory is a collection of different types of O HLEVU check-reorder â> inventory-itemli) H This has tremendous implications for NU TIR O mi za! ih za di Äb ah kak di bu NubLaa, program maintainability. As new item THe Hieratehical AtraHgement of Objects types are pk OE SATE POLA ject in a progr k ina, Pe Ee EMEA V OR ETEKI new procedures for check orders. zih oi pra RO oĹž DI, ana P rope pties, inherited fr ol pirent objec ts, bec olhe | are implemented, the code for the inven- order form in a business application has nore specifte for edeh ĹĄubordihate part. mi MW tory object never needs to be changed. properties such as items and guantity o dei This is unlike a conventional application means. In our everyday world, objects have both properties and behaviors: An oven has shape and size; it can bake and broil. Ji ke A v KI TAT KIPE - UT NE V mmi that would need to dispatch the correct re dic a i: n ObleciĹĄ Aa uÄi 8 lu: Gli dali ilels reorder procedure for each inventory TA Sa iÄ Mod SRE O resport to messages. z oprana dat Mskaaaki type. programs can be useh to dasenke MI ba [ Polpeti (<< DRookiventen environments in which a data-modeling | bbjecis Äi IMI di Fine-Tuned Inventory Control language defines objects and relation- | | | hi | | ih | In this example, polymorphism, COU- ships. In fact, object-oriented technology. ' go oa Mi ia tebi JE pled with both the inheritance of reor- ko 'originated with languages designed for - oi ââ â z â zma, â Pi der policies for standard parts and the simulation and is thriving in graphics KOK VSI umevno rerzvem || ability to customize and override the applications where the user route Type A IA KA ETA IH EI standard policies for particular parts, al- objects on the screen. However, the for- PartĹĄ | ala He dis. x | the sere, h lows an organization to program more al term object: has meaning beyond Heordet border | bide V |. complexity in the reordering logic of a ne commonsens ] ord. Pl lasi $ | |e rut | | Hi | | uring : icati thus givi sent physical entities such as inventory nij | | VEGE NEA and a significant competitive advantage. items, but they can also represent more A number of languages are available abstract entities such as stacks, num- for programmers interested in experi- zima lile-browsers, dispatchers or col- menting with object-oriented program- lections. mi a ae RS. ming. The oldest and perhaps the purest zi sei: L contains both data (proper- is Smalltalk, which has some excellent Les) and procedures (behaviors), a pro- implementations on small machines. The gramming object can be used to ia om 4 arize" : rammins conceni system enforces object-oriented pro- | onikjiea Rojude Sbenie K gat i | koorder | MA amming throughout and is an excel: oje made up of other objects, and oy Ik belev gen tool ea pure object-orient: | rowsers, which are procedures for ex- ide di gramming. : | amining files. Mis (di A different approach is to enhance The properties of an object can't be existing languages with object-oriented directly accessed from outside the ob- RS mem rea ae O MOLI HEJ: This is the approach taken ject. They are only manipulated by the peÄ | o oe by lu and Objective-C, which are behaviors of the object. The behaviors of both C extenslons, as well as Flavors, poe Sa only be ebay Bend. ROZA OE Em m nan which is a LISP extension. While thi mentation of the properties and zs panj program more complexity into the y ofa Conventional language, it has the disad: vantage of not forcing the programmer to use object-oriented technigues consis- Na vkona of an object is completely hid-. logic of' a manuf' acluring application, giving i - den from the < The objects dat NI ia A ie nana | and process a ae EO LANA tuned control and a significant competitive ad ns Aja, are encapsulated within ite. NIKE The te Rea must unlearn Poni Sana ea a edi iska | e procedura] pi ogramming style that zogo kovini pasa s JK zad pilone | Tim ingrained in anyone with pana a | tan ma zvomer order-entry appli- know anything about the inta, le programmin cation. The system has an oble ĹĄina ines of MA ne about the internal work- items. The inventory items in oh Oto Pp 8 experience. Old pro- order âwhich has behaviors that allow ply have to Ritem object. They sim. Bory of parts can themselves be objects, Ta aHing habits are hard to break. ansra z nee deja w which messages the leh : Peta Next week T'l look at examples of ob- | manipulation and inspection of its prop- inventory object wil O AIE such as serew or bolt. The inventory ob- | ject-orienteÂŤ rogramming i | len The definition might look like send nie EI ĹĄjte najo and t inherits all the behaviors of the col. â cations. ljam na 8 appli: | lection object and categ ry di In addition, object-oriented languages that with oÄ ni tegory object, so ââ DONE k Zrnec order; property variables: allow information to be organized con. sta ves no further work from the pro- 70 learn more about the subject of "? NET, lem, guantity; behaviors: veri: â ce ptually. The object definitions are o.- Brammer the code can add or delete in- these artici et O [y, process, back-order, add. Age ventory items. nase ih please call The James | Forcer, add. ganized in a class hierarchy, as shown in Pain Martin Report, an information ser An important, distin needs ne figure ze | Y, | Each of the inven types | | tnformation service made between a class obe HI Ba sne Pure A casa above sn objeri la ite... lo respond to tle ana va vpooled darterly, at (800) 242.1240. Bb ; Ve to respond to the mescaga "ah ; sraiih usod uperclass, and the one below is a sub. Roj message, check For information on sem; ' ple: Particular objects, The definition: ata Men Su reorder," Each of the particular tu aaa on semtnars, please class of object "order" cp sec of ine class. Objects in subclasses can inherit would define veheck particular ty contact (in the United States and Can- tion of the property variables. Each par- pije sl Ta properties and applies to that object, or bodem 4 Dee ada) Technology Transfer institute, â Ucular object, contains just the values The rs ol lhe classes above, ral check-reorder behaviors f mo 741 10th ne Santa Monica, Calif. [or he variables of that object. Mes- ject ? programmer working with an ob. superelasse sa HOT8 rom 90402 (213) 394.8305. m, Europe, con- , si riented language defines classes seli ses, Th plexity of differing tact Sava 2 Ne 1 SABeS are sent to t | a aB es c of reorder policies js c. sly | ni, Z New St., Carn, n he particular object, objects ranging from the general down from zisÄ aa, of tna ni lasoenu n, dei oi PA United Klepet. | Na iCatlo VoĹž17 (I4 505. T er mar j Sa Mi Mo zanke