Two-dimensional Arrays

version 6.0

Each of the array declaration commands can create or resize one-dimensional or two-dimensional arrays. Example:

   ARRAY TEXT (atTopics;100;50) ` Creates a text array composed of 100 rows of 50 columns

Two-dimensional arrays are essentially language objects; you can neither display nor print them.

In the previous example:

• atTopics is a two-dimensional array

• atTopics{8}{5} is the 5th element (5th column...) of the 8th row

• atTopics{20} is the 20th row and is itself a one-dimensional array

• Size of array(atTopics) returns 100, which is the number of rows

• Size of array(atTopics{17}) returns 50, which the number of columns for the 17th row

In the following example, a pointer to each field of each table in the database is stored in a two-dimensional array:

   C_LONGINT($vlLastTable;$vlLastField)
   C_LONGINT($vlFieldNumber)
      ` Create as many rows (empty and without columns) as there are tables
   $vlLastTable:=Get last table number
   ARRAY POINTER (<>apFields;$vlLastTable;0)  `2D array with X rows and zero columns
      ` For each table
   For ($vlTable;1;$vlLastTable)
      If(Is table number valid($vlTable))
         $vlLastField:=Get last field number($vlTable) 
            ` Give value of elements
         $vlColumnNumber:=0
         For ($vlField;1;$vlLastField)
            If(Is field number valid($vlTable;$vlField))
               $vlColumnNumber:=$vlColumnNumber+1
                  `Insert a column in a row of the table underway
               INSERT IN ARRAY(<>apFields{$vlTable};$vlColumnNumber;1)
                  `Assign the "cell" with the pointer
               <>apFields{$vlTable}{$vlColumnNumber}:=Field($vlTable;$vlField)
            End if 
         End for
      End if 
   End for

Provided that this two-dimensional array has been initialized, you can obtain the pointers to the fields for a particular table in the following way:

      ` Get the pointers to the fields for the table currently displayed at the screen:
   COPY ARRAY (<>apFields{Table(Current form table)};$apTheFieldsIamWorkingOn)
      ` Initialize Boolean and Date fields
   For ($vlElem;1;Size of array($apTheFieldsIamWorkingOn))
      Case of
         : (Type($apTheFieldsIamWorkingOn{$vlElem}->)=Is Date)
            $apTheFieldsIamWorkingOn{$vlElem}->:=Current date
         : (Type($apTheFieldsIamWorkingOn{$vlElem}->)=Is Boolean)
            $apTheFieldsIamWorkingOn{$vlElem}->:=True
      End case
   End for
   

Note: As this example suggests, rows of a two-dimensional arrays can be the same size or different sizes.

Arrays.