C++ How to Program, 10/e

... dangerous
23     // assignment. If string1 is modified, pointer ptr1 can
24     // become invalid.
25     ptr1 = string1.data(); // non-null terminated char array 
26
27     // output each character using pointer
28     for (size_t i{0}; i < length; ++i) {
29        cout << *(ptr1 + i); // use pointer arithmetic
30     }
31
32     cout << "\nptr2 is " << ptr2 << endl;
33     delete [] ptr2; // reclaim dynamically allocated memory
34  }

string string1 is STRINGS
string1 converted to a pointer-based string is STRINGS
ptr1 is STRINGS
ptr2 is STRINGS

The program declares a string, a size_t and two char pointers (lines 8–11). The string string1 is initialized to "STRINGS", ptr1 is initialized to nullptr and length is initialized to the length of string1. Memory of sufficient size to hold ...