Question

我正在尝试在c ++中创建类的对象数组。当我打印对象时，它会跳过数组的第一个元素（a [0]）。我读过很多论坛，但找不到问题。谁可以看到它？

class driver
{
private:
    string name;
    string surname;
    string categories;
    int salary, hours;   
public: 
void reads(string &n, string &p, string &c, int &s, int &h)
{
    std::cout<<"\t\t Give information about driver:"<<std::endl;
    std::cout<<"\t\t---------------------------------------\n";
    std::cout<<"\tGive name: "; std::cin>>n;
    std::cout<<"\tGive surname: "; std::cin>>p;
    std::cout<<"\tGive categories of driver license: "; std::cin>>c;
    std::cout<<"\tHow much he is payd for hour: "; std::cin>>s;
    std::cout<<"\tHow many hours did "<<n<<" "<<p<<" works? "; std::cin>>h;
} 
void print()
{
    std::cout<<name<<" "<<surname<<" ";
    std::cout<<"has categories "<<categories<<endl;
    std::cout<<"Salary per hour is "<<salary<<endl;
    std::cout<<"Driver had worked "<<hours<<" hours"<<endl;
    std::cout<<"Full payment is "<<salariu*hlucru<<" $"<<endl;
}
};
int main()
{
   string n,p,c;
   int s,h,nr,i;
 cout<<"Give nr of drivers:"; cin>>nr;
 driver *a[nr];
 for(i=0;i<nr;i++)
 {
     a[i]=new driver(n,p,c,s,h);
     a[i]->reads(n,p,c,s,h);
     cout<<endl;
 }
 for(i=0;i<nr;i++)
 {
     a[i]->print();
     cout<<endl;
 }

Answer 1

您的reads()函数未达到预期的效果。它正在将数据读取到您的main()字符串中，然后将这些字符串传递给您创建的下一个对象。
您的a[0]具有未初始化的成员，这就是您所看到的“不打印a [0]”

您的代码可能看起来应该更像这样：

void reads() {
    //all the std::cout calls should also be here
    std::cin >> name;
    std::cin >> surname; //etc. 
}

在您的main()中：

int main()
{
    int nr;
    cout << "Give nr of drivers:"; 
    cin >> nr;
    driver* a = new driver[nr]; //use std::vector instead!
    for(int i = 0; i < nr; i++)
    {
        a[i].reads();
        cout<<endl;
    }
    for(int i = 0; i < nr; i++)
    {
        a[i].print();
        cout<<endl;
    }
    delete[] a;
}

创建对象数组C ++

1 个答案: