[实参] 与 [形参]

#include <stdio.h>

char * GetStr(char *p)
{
    p = "hello world";
    return p;
}

int main()
{
    char *str = NULL;
  
    if(NULL != GetStr(str))
    {
        printf("str = %s\n",str);
    }
    return 0;
}