//----------- begin find.C void find(int begin_age = 0, int end_age = 10) { gSystem->Load("Person.so"); TFile *f = new TFile("test.root"); TIter next(f->GetListOfKeys()); TKey *key; while (key = (TKey*)next()) { Person *t = (Person *) key->Read(); if (t->get_age() >= begin_age && t->get_age() <= end_age) { printf("age = %d, height = %f\n", t } delete t; } } //----------- end find.C