HP 3000 Manuals HP 3000 Manuals
Arrays and Array Items
An array is a combination of one or more items of the same type. Each
item in an array (also called a component of an array) is treated exactly
like a normal item. Arrays are defined in a data dictionary; you can
manipulate but not create arrays in HP ALLBASE/BRW.
Characteristics
Arrays have these characteristics:
* Each array item is referenced by the array name followed by an
index in parentheses, as shown here:
TURNOVER(4)
This will reference the fourth item (or component) of the array
TURNOVER.
TURNOVER ((MONTH + 4) / 2)
This will reference the item whose index is the result of the
expression MONTH + 4 / 2.
* As with items, if the array name is not unique, it can be preceded
by the source table name followed by a period; for example:
CUSTOMERS.TURNOVER(?MONTH)
This will reference the item in the array TURNOVER (in source
table CUSTOMERS) whose index is equal to the value of the
parameter ?MONTH.
* The first array component has an index of 1.
* If no index is specified, the first array component is selected.
That is, if you specify TURNOVER (in a calculation or in a
lineset) without an index, the value of TURNOVER (1)is used in the
calculation (or is printed).
* If the index points to an array component that does not exist (for
example, an array TURNOVER has 12 components, and the array item
is TURN OVER(13)), an INDEXVIOLATION occurs. See "Exception
Handling" later in this chapter.
* The array index must be of the type Integer.
* Array components can be of any HP ALLBASE/BRW type (so long as all
the components of an array are the same type) that is; Numeric,
Real, Integer, String, Date, or Time. They behave exactly as
normal items of their type. For example, they have a single value
per record, and so on.
* Arrays are usually referenced by component; only on the Project
Items and Output File screens do you refer to an entire array.
HP ALLBASE/BRW makes no distinction between normal items and array
items. (To HP ALLBASE/BRW, a normal item is an array with one
component.)
Related Sections
* Arguments
* Aggregate/Array Operations
* Calculation Language
* Naming Conventions