public IMobilePlan GetPlan(string planName) { IMobilePlan plan = NullObject.Instance(); switch (planName) { case "1": { plan = new TalkTooMuch28(); break; } case "2": { plan = new TalkTooMuch100(); break; } case "3": { plan = new PostPaidSaver(); break; } case "4": { plan = new PostPaidExclusive(); break; } default: { break; } } return(plan); }
static NullObject() { instance = new NullObject(); }