C++ Pointers and References

Pointers

C++ has the same memory management capabilities as C, including working with pointers.

#include <iostream>

int main() {
    int a = 5;
    int *ptr = a;
    std::cout << ptr < '\n';
    std::cout << *ptr < '\n';
    return 0;
}

This prints a hexadecimal address like 0x7ffe1a8207dc and 5.

References

C++ adds the concept of references, which are essentially pointers that cannot be null. In fact references are often internally implemented as pointers.

#include <iostream>

int main() {
    int a = 5;
    int &ref = a;
    std::cout << ref < '\n';
    return 0;
}

This prints 5.

Pointers vs. References

Generally it is recommended to use references unless they are unavailable, or unless a null address is within a function's domain.

References are not objects. See here: "there are no arrays of references, no pointers to references, and no references to references".

int& a[3]; // error
int&* p;   // error
int& &r;   // error

Some functions are written to properly handle the case of a null pointer. This is perfectly valid and negates the benefits of references.

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