Objects

The OS/400 operating system is object-based; this means the fundamental software entities on the iSeries can be understood and manipulated as objects existing within a uniform, simple conceptual framework. All OS/400 objects have certain common properties; for example, a name, a creation date, an owner; and can be subjected to certain common methods, such as saving, moving, and deleting.

Objects ensure better integrity and better modularization. The OS/400 objects also provide a simple intuitive way of understanding system software. The statements of OS/400’s CL command language have highly uniform verb/object syntax; for example Create Data area (CRTDTAARA), Delete data area (DLTDTAARA), Display data area (DSPDTAARA). You may consider this as being similar to the imperative tense used for simple English commands such as "Read this" or "Stop that." The distinction between objects and the methods that operate on them corresponds to the noun/verb distinction found in natural languages.

By adopting a consistent syntax in its commands and other interfaces, OS/400 is able to harness our innate capabilities to generalize rules and formulate new instances so that you can successfully use new software or cope with new situations.

As an illustration of what can be achieved with useful names, consider the following three lists of names that show three different sets of unique names for the same set of objects:

List 1 List 2 List 3

ABC0001 PGM0001 DSPCUS

ABC0002 PGM0002 DSPCUSDTL

ABC0201 FIL0001 CUSDTA

ABC0210 FIL0010 ORDHDR

ABC0220 FIL0020 ORDDTA

In the first list, the names are meaningless. You must already know about object ABC0001 to know what it is and its capabilities. Although you might be able to make use of rules like "objects with a range of 001 to 100 are programs" to glean additional information, the rules are as arbitrary as the names. In the second list, you can tell the type of the object from the name (PGM or FIL), but little else. In the third list, you can make an educated guess as to what each of object is, provided that you are aware of normal OS/400 conventions.

In doing so, you are employing naturalistic mechanisms: the use of a limited vocabulary of "words" which always have a similar meaning, (DSP-Display, DTA-Data), and the use of a simple syntax. The essence of the syntax is to use a simple imperative verb word (DSP) followed by an object word (CUS) to indicate a procedural verb object (DSPCUS), as opposed to an adjective (CUS) and a noun (DTA) to indicate a passive noun object (CUSDTA). A third point to note is that the OS/400 convention for systematically deriving mnemonics from significant consonants is naturalistic as consonants are generally more easily remembered.