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C++ References


Creating References

A reference variable is a "reference" to an existing variable, and it is created with the & operator:

string food = "Pizza";  // food variable
string &meal = food;    // reference to food

Now, we can use either the variable name food or the reference name meal to refer to the food variable:

Example

string food = "Pizza";
string &meal = food;

cout << food << "\n";  // Outputs Pizza
cout << meal << "\n";  // Outputs Pizza
Run example »

Memory Address

In the example above, the & operator was used to create a reference variable. But it can also be used to get the memory address of a variable, which is the location of where the variable is stored on the computer.

When a variable is created in C++, a memory address is assigned to the variable. And when we assign a value to the variable, it is stored in this memory address.

To access it, use the & operator, and the result will represent where the variable is stored:

Example

string food = "Pizza";

cout << &food; // Outputs 0x6dfed4
Run example »

Note: The memory address is in hexidecimal form (0x..). Note that you may not get the same result in your program.

And why is it useful to know the memory address?

References and Pointers (which you will learn about in the next chapter) are important in C++, because they give you the ability to manipulate the data in the computer's memory - which can reduce the code and improve the perfomance.

These two features are one of the things that make C++ stand out from other programming langues, like Python and Java.