trf_byValue

program contoh2;
uses crt;

procedure tukar(x, y: integer);
var z: integer;
begin
    z:=x;
    x:=y;
    y:=z;
end;

var a, b: integer;
begin
    clrscr;
    a := 2;
    b := 9;
    tukar(a,b);
    writeln('a=', a, ' b=', b);
    readkey;
end.