nullptr

Learn the modern null pointer concept with nullptr.

nullptr

nullptr is the pointer value meaning 'points nowhere'. In old C++ you would use NULL or 0, but modern C++ prefers nullptr because it is type-safe.

Initializing a pointer with int* p = nullptr; states clearly that p has no target yet. Later you can check whether it is empty with if (p == nullptr). This is the safety check before dereferencing.

Null check

Before dereferencing a pointer with *p, it is a good habit to check whether it is null. Dereferencing a null pointer is undefined behavior; the program may crash.

The check: if (p != nullptr) { std::cout << *p; }. This prints the value only if p is not null. Null pointers are an explicit way to express 'no target yet'; so you meet them often in modern C++ code.

Exercise Null pointer check

Declare int* p = nullptr;. Check with if (p == nullptr); if true, print "Boş" with std::cout (with a newline).

Show example solution

#include <iostream>

int main() {
    int* p = nullptr;
    if (p == nullptr) {
        std::cout << "Boş\n";
    }
    return 0;
}

Test yourself

nullptr assignment
```
int* p = ____;
```
Show answer
```
int* p = nullptr;
```
What is nullptr?
- A value that points nowhere
- An empty variable
- A pointer type
- A reference
Show answer

A value that points nowhere — nullptr is the pointer value that points nowhere.
Match each expression to its meaning

nullptr

Null pointer
if (p == nullptr)

Check
int*

Pointer type
p == nullptr

Comparison

Next lesson: Pointer arithmetic

We Are Enhancing Your Experience

Cookie Preferences

Strictly Necessary Cookies

Analytical Cookies