function IsDigitalField(dbf, f :integer): integer;

IsDigitalField returns a non-zero value (1) for numeric (Numeric, Float, Double, Currency, Integer) fields.


var
  dbf :integer;
  n :integer;
begin
  dbf := OpenBase( 'filename.dbf' );
  if dbf <> 0 then
  begin
    n := FieldNumber(dbf, 'SALARY');
    if n >= 0 then
       if IsDigitalField(dbf, n) then 
          showmessage( 'It is a numeric.' );
    CloseBase(dbf);
  end;
end.