c - 错误: Incompatible integer to pointer conversion passing 'unsigned long'

Question

将指向长整数的指针作为函数参数传递时，我收到以下警告消息。

warning: incompatible integer to pointer conversion passing 'unsigned long' to parameter of type 'unsigned long *'; remove * [-Wint-conversion] reverse(*n1);

Recursion_Reverse.c:16:29: note: passing argument to parameter 'n1' here: void reverse(unsigned long *n1)

这是代码片段。提前致谢!

void reverse(unsigned long *);

int main() { 
    unsigned long n; 

    printf("\nEnter Any Nnmber:");    
    scanf("%lu",&n); 

    reverse(&n);    
    printf("\nAfter Reverse,n=%lu\n",n); 

    return 0;
}


void reverse(unsigned long *n1) {
    unsigned long sum=0;
    if(*n1>0) 
    {
        sum=(sum*10)+(*n1%10);
        *n1/=10;
        reverse(*n1);
    }

    *n1=sum;
}

Answer 1

从您的 void reverse(unsigned long *n1) 函数内部，您递归地调用它:

reverse(*n1);

因此，您传递的是直接 unsigned long 而不是其指针。正如您所期望的，只需将其指针更改为:

reverse(n1);