网站后台建设软件,wordpress 注册美化,高端品牌汽车,长安h5网站建设c语言中将函数指针作为形参Prerequisite: An Example of Null pointer in C 先决条件#xff1a; C中的空指针示例 Any pointer that contains a valid memory address can be made as a NULL pointer by assigning 0. 通过分配0#xff0c;可以将包含有效内存地址的任何指…c语言中将函数指针作为形参Prerequisite: An Example of Null pointer in C 先决条件 C中的空指针示例 Any pointer that contains a valid memory address can be made as a NULL pointer by assigning 0. 通过分配0可以将包含有效内存地址的任何指针设置为NULL指针 。 Example: 例 Here, firstly ptr is initialized by the address of num, so it is not a NULL pointer, after that, we are assigning 0 to the ptr, and then it will become a NULL pointer. 在这里首先ptr由num的地址初始化因此它不是NULL指针此后我们为ptr分配0 然后它将成为NULL指针。 Program: 程序 #include stdio.h
int main(void) {
int num 10;
int *ptr num;
//we can also check with 0 instesd of NULL
if(ptr NULL)
printf(ptr: NULL\n);
else
printf(ptr: NOT NULL\n);
//assigning 0
ptr 0;
if(ptr NULL)
printf(ptr: NULL\n);
else
printf(ptr: NOT NULL\n);
return 0;
}
Output 输出量 ptr: NOT NULL
ptr: NULL
翻译自: https://www.includehelp.com/c-programs/making-a-valid-pointer-as-null-pointer-in-c.aspxc语言中将函数指针作为形参
