如果我写
int zero = 0;
void *p1 = (void *)0;
void *p2 = (void *)(int)0;
void *p3 = (void *)(0 /*no-op, but does it affect the next zero?*/, 0);
void *p4 = (void *)zero; // For reference, this is a pointer to address zero
void *p5 = 0; // For reference, this is a null pointer
void *p6 = NULL; // For reference, this is a null pointer
void *p7 = nullptr; // For reference, this is a null pointer …Run Code Online (Sandbox Code Playgroud)