Difference between revisions of "DECLARE"

Revision as of 09:58, 19 May 2014

Purpose

Declare an array

Syntax

DECLARE <array>[<expN>] | (<expN>)

DECLARE <array>[<expN1>,<expN2>] | (<expN1>,<expN2>)

DECLARE <array>[] | ()

See Also

AAVERAGE(), ACOPY(), ADEL(), ADIR(), AFIELDS(), AFILL(), AINS(), ALEN(), AMAX(), AMIN(), APPEND FROM ARRAY, ARRAY(), ASORT(), ASUM(), COPY TO ARRAY, DIMENSION, GATHER, GETMEMBER(), IN_ARRAY(), IS_ARRAY(), LOCAL, NAMESPACE, NAMESPACE(), PRIVATE, PUBLIC, RELEASE, RESTORE, SAVE, SCATTER, VARINFO()

Description

The DECLARE command is used to declare fixed one or two-dimensional arrays and dynamic arrays.

For fixed arrays, the array size is set at its declaration. Dynamic arrays are declared without a size. Array subscripts can be referenced using square brackets or round brackets.

[<expN>] | (<expN>)

For one-dimensional arrays, [<expN>] specifies the total number of elements in the array. Elements are subsequently referenced using the notation <array>[<expN>] or <array>(<expN>).

[<expN1>,<expN2>] | (<expN1>,<expN2>)

For two-dimensional arrays, <expN1> represents the number of rows and <expN2> represents the number of columns in the array. Elements are subsequently referenced by <array>[<expN1>,<expN2>] or <array>(<expN1>,<expN2>). The elements of a two dimensional array can also be referenced, as if the array were one dimensional, using <array>[<expN1>] or <array>(<expN>).

Fixed arrays can be declared as any size. Values are assigned into arrays using the '=' operator. Arrays can then be used in a similar way to memory variables. Complete arrays can be initialized with one assignment. Array references start at 1,1 for two-dimensional arrays, and 1 for one-dimensional arrays.

[] | ()

Dynamic arrays are declared without specifying a size. Elements are added using arrayname.element syntax.

aDynarray.name = [Lianja Inc]
aDynarray.email = [sales@lianja.com]

They can then be referenced by element number or by element name.

? aDynarray.name
Lianja Inc
? aDynarray[2]
sales@lianja.com

Notes: The brackets shown for this command do not indicate optional expressions but are a necessary part of the syntax. Arrays can also be declared using any of the scoping commands: LOCAL, PRIVATE and PUBLIC.

Example

// Declare one-dimensional array of 4000 elements
declare aTable[4000]
// Assign 0 to all elements
aTable = 0
// Insert individual element values into array
aTable[1] = 10
aTable[2] = "Hello"
aTable[3] = "World"
aTable[4] = date()
// Print value of element 2
? aTable[2]
Hello
 
// Another example
declare twodim[3,3]
twodim[2,3] = "hello world"
? twodim[6]
hello world
 
// Another example
use payroll
declare aPayroll[reccount(), fcount()]
copy to array aPayroll for city = "LONDON"
 
// Dynamic array
declare aDynarray[]
aDynarray.name = [Lianja Inc]
? aDynarray.name
Lianja Inc
? aDynarray[1]
Lianja Inc