What is the meaning of reference in C++?

In C++, a reference is a mechanism used to refer to variables. It allows us to use an existing variable as an alias to access the value of another existing variable, instead of creating a new copy.

A reference can be seen as an alias for an existing variable, accessing its value through the variable’s memory address. References offer a convenient way to pass parameters, return values, and manipulate objects, reducing unnecessary memory overhead and copying operations.

The declaration of a reference is done by adding an “&” symbol in front of the variable type, for example int& ref. References must be initialized at the time of definition, and once initialized, they will always refer to the same object and cannot be changed to refer to another object.

Here are some characteristics and applications of citations:

1. A reference is an alias for an existing object, operations on a reference are actually operations on the original object.
2. Once a reference is initialized, it cannot be reassigned to another object.
3. Quotes can be used as parameters and return values in functions, allowing for the passing and manipulation of objects.
4. Using references can simplify the use of pointers, as they provide direct access to the members of an object.
5. Quoting can be used for iterator operations, providing a concise way to iterate through the elements in a container.

It is important to note that references and pointers are different concepts. References do not require the dereference operator * when used, while pointers need the dereference operator to access the value pointed to by the pointer. In addition, once a reference is initialized, it cannot change the object it points to, while a pointer can be reassigned to point to another object.