As it says here: How to use delete with a variable pointed to by two pointers? one can only delete once, then all pointers won't work, but the code below:
#include<iostream>
using namespace std;
int main(){
string * str1 = new string("abc");
string * str2 = str1;
cout<< *str2 <<endl;
delete str1;
str1 = NULL;
cout<< *str2<<endl;
}
the output is:
abc
abc
so, what's the matter?
Once you have deleted a pointer, accessing it is undefined behavior and may print old contents sometimes, may crash sometimes or may do something beyond thinking some other time.
To handle a case of deleting shared pointer, use std::shared_ptr or similar reference counting manager wrapper instead of naked pointers.
One of the outcomes of undefined behavior is that is might seem to work. And dereferencing a pointer to a destructed object (like you do with cout<< *str2<<endl;) is undefined behavior.
