Why should we use nullptr instead of NULL or 0?

In modern C++, using nullptr is preferred over NULL or 0 when dealing with pointers.

Here’s why:

• The type of nullptr is std::nullptr_t.

• std::nullptr_t can be implicitly converted to any pointer type, but not to an integer.

• Because of this, nullptr behaves like a universal pointer — it works with all raw pointer types, without introducing ambiguity.

🔸 Benefits of nullptr

• Avoids overload resolution issues: When passing NULL or 0, the compiler might get confused if a function is overloaded to take either an int or a pointer. nullptr solves this problem.

• Improves code clarity: Especially when used with auto, nullptr makes the programmer’s intent clearer — you're assigning a null pointer, not a zero value.

💡 Things to Remember

• Always prefer nullptr over NULL or 0 in C++11 and later.

• Avoid overloading functions on pointer and integer types — it leads to confusing and error-prone code.

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✅ Example

cppCopyEditvoid process(int);
void process(char*);

process(0);      // Calls process(int) — maybe not what you intended
process(NULL);   // Still might call process(int), depending on the platform
process(nullptr); // Always calls process(char*) — clear and unambiguous

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✍️ Final Tip

Using nullptr is a small but powerful habit that helps you write cleaner, safer, and more modern C++ code.