Pointers and References in C++

Pointers and references are two of the most powerful features of C++. A pointer is a variable that holds the address of another variable, while a reference is an alias for another variable.

Let’s look at an example of declaring and using a pointer:

#include <iostream>

int main()
{
    int x = 10;
    int *ptr = &x;
 
    std::cout << "x = " << x << std::endl;
    std::cout << "ptr = " << ptr << std::endl;
 
    *ptr = 20;
 
    std::cout << "x = " << x << std::endl;
 
    return 0;
}

Output

x = 10
ptr = 0x7ffee5e90d4c
x = 20

In this example, we have declared a pointer called ptr and initialized it with the address of the variable x. We have then used the cout stream to print out the value of x and the address of ptr. Finally, we have used the dereference operator (*) to change the value of x.