Prinsip Open/Closed (OCP) nyebutake manawa entitas piranti lunak kudu mbukak kanggo extension nanging nutup kanggo modifikasi: sampeyan kudu nambah tingkah laku anyar kanthi nambah kode anyar, ora kanthi nyunting kode sing wis ana lan wis diuji.
Menapa penting
():
shape.kind == : * shape.r **
shape.kind == : shape.s **
shape.kind == : shape.w * shape.h
