C语言二级指针做函数参数改变该指针的指向

一、测试代码如下：

//C语言二级指针做函数参数改变该指针的指向#include <stdio.h>  void change_pointer(char **pp){   char *str="the pointer has been changed! \n";   *pp=str;}int main(int argc, char **argv)  {      char *p=NULL;printf("before change pointer,p=%s\n",p);  change_pointer(&p);    printf("after change pointer,p=%s\n",p);      return 0;  } 

二、p本来指向null，经过changer_pointer函数后p指向"the pointer has been changed!"字符串了。

三、运行结果：