C++ Pointers
Creating Pointers
You learned from the previous chapter that we can get the memory address of a variable by using the &
operator:
Example
string food = "Pizza"; // A food variable of type string
cout << food; // Outputs the value of food (Pizza)
cout << &food; // Outputs the memory address of food (0x6dfed4)
Try it Yourself »
A pointer however, is a variable that stores the memory address as its value.
A pointer variable points to a data type (like int
or string
) of the same type, and is created with the *
operator. The address of the variable you're working with is assigned to the pointer:
Example
string food = "Pizza"; // A food variable of type string
string* ptr = &food; // A pointer variable, with the name ptr, that stores the address of food
// Output the value of food (Pizza)
cout << food << "\n";
// Output the memory address of food (0x6dfed4)
cout << &food << "\n";
// Output the memory address of food with the pointer (0x6dfed4)
cout << ptr << "\n";
Try it Yourself »
Example explained
Create a pointer variable with the name ptr
, that points to a string
variable, by using the asterisk sign *
(string* ptr
). Note that the type of the pointer has to match the type of the variable you're working with.
Use the &
operator to store the memory address of the variable called food
, and assign it to the pointer.
Now, ptr
holds the value of food
's memory address.
Tip: There are three ways to declare pointer variables, but the first way is preferred:
string* mystring; // Preferred
string *mystring;
string * mystring;