sort_fieldset_array

The function sort_fieldset_array sorts the elements of a FIELDSET array and stores the sorted elements in a second array.

 sort_fieldset_array ( input;output;field;number of elements to sort )

The function sort_fieldset_array is of type BOOL and has four parameters:

1. input; ARRAY of type FIELDSET. This array contains the elements that must be sorted.
2. output; ARRAY of type FIELDSET. This array receives the sorted elements.
3. field; TEXT. This is the Field in the FIELDSET that is used as the key to sort the array. If this Field is not present in the FIELDSET, it is considered empty.
4. number of elements to sort; NUMBER. This is the number of elements in the array that must be sorted starting from the first element. This can either be a number or a NUMBER variable or expression.

The function sort_fieldset_array returns TRUE if the array was sorted successfully, and FALSE in one of the following conditions:

• If the number of elements parameter to be sorted is negative or 0.
• If the function sort_fieldset_array fails the output array is unmodified. The input array is not modified by the function. The output array receives the sorted values from the input array. If the output array is larger than the number of sorted elements, those elements outside the sorted range are left unmodified.
• The function sort_fieldset_array performs an alphabetical sort on the text elements using the ANSI code page.

An example is provided here.

DDATASTRUCTURE DS
  BEGIN
    ARRAY FIELDSET Array[0]
  END

DECLARE input DEFINED_AS DS
DECLARE output DEFINED_AS DS

NUMBER i

ASSIGN input.Array[1].Key := "c"
ASSIGN input.Array[2].Key := "d"
ASSIGN input.Array[3].Key := "a"
ASSIGN input.Array[4].Key := "b"

IF sort_fieldset_array (input.Array; output.Array; "Key"; 4) THEN
  FOR i FROM 1 UPTO 4
  DO
#
@(i) @(output.Array[i].Key)
#
  OD
ELSE
#
Failed to sort the input.
#
  STOP
FI

The type BOOL of the sort_filedset_array function is used to implement error handling. If the sort succeeds, the return value of the function is TRUE, the IF statement becomes TRUE, and the THEN part is executed. If the return is FALSE, the ELSE part of the IF statement is executed.