c++ - 将指针传递给函数不返回值

Question

在下面的例子中我得到 NumRecPrinted = 0 ，即 num 是 0

int main()
{
    int demo(int *NumRecPrinted);
    int num = 0;
    demo(&num);
    cout << "NumRecPrinted=" << num;    <<<< Prints 0
    return 0;
}

int demo (int *NumRecPrinted)

{
    int no_of_records = 11;
    NumRecPrinted = &no_of_records;
}

Answer 1

您正在将地址分配给指针，而不是将值分配给所指向的对象。试试这样吧

int demo (int *NumRecPrinted)
{
     int no_of_records = 11;
     *NumRecPrinted = no_of_records; 
}