Lvalue References in C++
This post and the examples are from the Microsoft C++ Documentation.
An lvalue reference is another name of an object. An lvalue reference declaration consists of an optional list of specifiers followed by a reference declarator. A reference must be initialized and cannot be changed.
An object whose address can be converted to a pointer type can also be converted to the similar reference type. For example, any object whose address can be converted to type char * can also be converted to char &.
Note that the reference declaration is not the same as the address-of operator. When the & identifier is preceded by a type (e.g. int, char), it is used as a reference declaration. When the & identifier is not preceded by a type, it is as the address-of operator.
Below is an example of using the reference to a Course object.
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#include <iostream>
using namespace std;
struct Course
{
char* Name;
char* Time;
};
int main()
{
// Declare a Course object.
Course myCourse;
// Declare a reference to the Course object.
Course& rCourse = myCourse;
// Set the fields of the Course object.
// Updating either variable changes the same object.
myCourse.Name = "Operating System";
rCourse.Time = "Wednesdays";
// Print the fields of the Person object to the console.
cout << rCourse.Name << " is on " << myCourse.Time << endl;
}
The output is as follows. Because rFriend is a reference to myFriend, updating either variable changes the same object.
1
Operating System is on Wednesdays