Lecture Preview: Memory and Pointers

(Suggested book reading: Programming Abstractions in C++, 11.2, 12.1, 12.5)

Today we will learn about a C++ feature called pointers. A pointer stores the memory address of another value. Get the address of an existing value by preceding it with & . Declare a pointer by following a data type with * . You can also follow a pointer to the memory address at which it points by preceding its name with * . Here is a brief example: 

int x = 42;
int* p = &x;
cout <<  p << endl;   // 0x7f8e20
cout << *p << endl;   // 42
*p = 99;
cout << x << endl;    // 99

We use the special value nullptr to indicate the pointer variable does not hold a valid memory location. nullptr is a special value in C++ representing a pointer to nothing; it indicates the lack of any further data.

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