character join concat/pipe in oracle reports

function remkFormula return Char is

begin
return(:abs_day ||' day absent = ' ||  :abs_day*2 ||' deduction');
end;


abs_day---Number
remk  ---char

function remkFormula return Char is
begin
    if :abs_day <> 0 then
  return(:abs_day ||' day absent = ' ||:abs_day*2 || ' days deduction');

        else return(''); end if;
       
end;

/*

    if :abs_day <> 0 then
  return(:abs_day ||' day absent = ' ||:abs_day*2 || ' days deduction');
    elsif :abs_day = 0 then
        return('');
        else null; end if;
*/