zakaster

sorry i used a duplicated name, for example if i input another name, input new name for person:hello address of new_name = 000000000061FD90 p name = hello address of dummy = 000000000061FDE0 p name = hello

hello sir, really good topic. i have a question regarding the example on deep and shallow copy though, struct person { char* name; }; void get_person(struct person* p) { char new_name[20]; // on stack, gets freed when function returned printf("input new name for person:"); scanf("%s", &new_name); p->name = new_name; printf("address of new_name = %p\n", &new_name[0]); } void eg_test_copy2(void) { struct person p = {"alex"}; get_person(&p); printf("p name = %s\n", p.name); char dummy[20] = { 0 }; printf("address of dummy = %p\n", &dummy[0]); printf("p name = %s\n", p.name); } if i call function `eg_test_copy2`, i noticed that the memory allocated for `new_name` never gets cleared, the output will be input new name for person:alex address of new_name = 000000000061FD90 p name = alex address of dummy = 000000000061FDE0 p name = alex and the address for `dummy` actually starts after the address of new_name + 4 bytes x 20, and i can still access the old name, is this weired