To define a reference variable in C++, you use the & symbol after the variable type. Here’s an example:

#include <iostream>

int main() {
    int num = 10;
    int& ref = num; // reference variable to alias 'num'

    std::cout << "Value of num: " << num << std::endl;
    std::cout << "Value of ref: " << ref << std::endl;

    ref = 20; // modifying the value through the reference

    std::cout << "Value of num after modification: " << num << std::endl;

    return 0;
}

In this example, we define an integer variable num and a reference variable ref which is assigned the value of num. Any modifications made to ref will also modify num because ref is just an alias for num.

When executed, the output will be:

Value of num: 10
Value of ref: 10
Value of num after modification: 20

You can see that modifying ref also changes the value of num.

It’s important to note that reference variables must be initialized when they are declared. Once a reference is assigned, it cannot be changed to refer to another variable. This makes it different from a traditional pointer.

References provide a convenient way to work with variables in C++. By using references, you can create a more readable and efficient code, especially when dealing with large data structures or passing variables between functions.

#C++ #References