- In C language
#define NULL((void*)0) - In C++ language
#ifndef NULL
#ifdef_cplusplus
#define NULL 0
#else
#define NULL((void*)0)
#endif
#endif
- In C++11, nullptr is used instead of (void*)0, and NULL only means 0;
#ifndef NULL
#ifdef_cplusplus
#define NULL 0
#else
#define NULL((void*)0)
#endif
#endif