Sorting a string array

I had a need to sort a string array and I found some code on Real Gagnon’s website that sorted numbers by creating a DataStore/DataWindow on the fly and used that to sort. Someone added a comment that for strings you need to define the column as char to avoid errors. I improved the code by adding a loop to determine the longest string in the array and using that when defining the DataWindow source.

public function boolean of_sortarray (ref string as_array[], string as_order);// —————————————————————————–

// SCRIPT:     of_SortArray

//

// PURPOSE:    This function sorts the passed array using a DataStore created

// on-the-fly.

//

// This is based on code from Real Gagnon:

// http://www.rgagnon.com/pbdetails/pb-0114.html

//

// ARGUMENTS:  as_array – Array of values to sort

// as_order – The sort order:

//

// Order value Resulting sort order

// ———————— —————————

// a, asc, ascending, ai, i Case-insensitive ascending

// d, desc, descending, di Case-insensitive descending

// as, s Case-sensitive ascending

// ds Case-sensitive descending

//

// DATE        PROG/ID DESCRIPTION OF CHANGE / REASON

// ———-  ——– —————————————————–

// 09/27/2016 RolandS Initial Coding

// —————————————————————————–

DataStore lds_sort

String ls_source, ls_error

Long ll_idx, ll_max, ll_len, ll_maxlen

Integer li_rc

// determine maximum length of values

ll_max = UpperBound(as_array)

For ll_idx = 1 To ll_max

  ll_len = Len(as_array[ll_idx])

  If ll_len > ll_maxlen Then

  ll_maxlen = ll_len

  End If

Next

// build DataWindow source code

ls_source = “release 6; datawindow( processing=0 ) ” + &

  “table(column=(type=char(” + String(ll_maxlen) + &

  “) name=array dbname=~”array~” ) )”

// create DataStore

lds_sort = Create DataStore

li_rc = lds_sort.Create(ls_source, ls_error)

If li_rc = 1 Then

  // put data into DataStore

  lds_sort.Object.array.Current = as_array

  // sort the data

  lds_sort.SetSort(“array ” + as_order)

  lds_sort.Sort()

  // set array to sorted data

  as_array = lds_sort.Object.array.Current

Else

  Return False

End If

// destroy DataStore

Destroy lds_sort

Return True

end function