Question

将整数推送到vector中的语法是什么？在Custothe类中？

class Customer {
vector <int> loyalID;
}

int main {
Customer customer;

vector<Customer>customers;

customers.push_back(/*some integers to go into loyalID vector*/);
}

Answer 1

将向量公开（不推荐）或在类中编写公共成员函数：

void Customer::push_back(int i)
{
    loyalID.push_back(i);
}

在main中，customers中有元素后，您可以写下这样的内容：

customers[0].push_back(10);

Answer 2

loyalID是Customer的私有字段。要么公开（不推荐），要么添加公共方法：

class Customer {
  vector <int> loyalID;

  public:
  void addLoyalId(int id)
  {
    loyalID.push_back(id);
  }
}

访问忠诚的ID：

class Customer {
  vector <int> loyalID;

  public:
  void addLoyalId(int id)
  {
    loyalID.push_back(id);
  }

  std::vector<int>::iterator begin() const { return _loyalID.begin(); }
  std::vector<int>::iterator end() const { return _loyalID.end(); }
}

用法：

Customer c;
c.addLoyalId(1);
c.addLoyalId(2);
c.addLoyalId(3);

for (auto&& id : c)
{
  std::cout << id << " ";
} // will print "1 2 3"

STL向量内部类访问推送

2 个答案: