References - &

Lesson 8 of 14 in Coddy's C++ Pointers course.

References are a special kind of variable that represents an alternative name (alias) of an already existing variable. After the reference is defined to refer to a certain variable, that variable can be accessed with its name or with the reference.

References are particularly useful when you want to modify the original variable within a function or when passing large structures efficiently. They allow you to work with that variable directly without needing to use pointers.

int a = 10;
int &ref = a; // ref is a reference to a
   
ref = 20; // Changes the value of a to 20
cout << "a = " << a;

Output:
a = 20

References work very similarly to pointers, but they are a different approach to changing a variable's data without using the variable itself, they are very useful when using functions which you will see in the next lesson

Test yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

Test yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

Test yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

Challenge

Easy

You will be given two numbers, and input them into the variables a and b accordingly. Create a reference refA that refers to a and a reference refB that refers to b. Multiply refA by 4, and subtract a from refB

Note: Do NOT change the default code

Try it yourself

#include <iostream>

using namespace std;

int main() {

    // Enter your code here

    // DO NOT CHANGE THE CODE BELOW
    cout << "a = " << a << endl;
    cout << "b = " << b << endl;
    cout << "refA = " << refA << endl;
    cout << "refB = " << refB << endl;
    // DO NOT CHANGE THE CODE ABOVE
}

All lessons in C++ Pointers

1Pointer Fundamentals

Introduction to Pointers Declaration & Initialization Arithmetic - Assignment Arithmetic - Operations Const Pointers Pointers & Arrays

2Pointers & References

Pointers as ParametersReferences - &References as Parameters Pointers vs References

3Dynamic Memory Allocation

New & Delete Operators Memory Leaks Dynamic Array Dynamic Array - Insertion