如何找到向量中大于某个数字的所有元素？ [复制]

Question

假设我有一些课程。

Class Example
{
int amount;
string name;
}
//constructors
...........
.....
int geAmount()
{
return amount;
}

然后我创建对象向量。

Vector <Example> vector1;

如何找到数量大于的所有元素 20（例如）？ 我想打印它们..

例如我有 3 个对象。

Name=abc amount 5
Name=bcd amount 25
Name=dcg amount 45

所以我只想打印最后两个对象。

Answer 1

您将使用循环并访问amount 成员：

#include <iostream>
#include <vector>
#include <string>

struct Record
{
  int amount;
  std::string name;
};

static const Record database[] =
{
  {  5, "Padme"},
  {100, "Luke"},
  { 15, "Han"},
  { 50, "Anakin"},
};
const size_t database_size =
    sizeof(database) / sizeof(database[0]);

int main()
{
    std::vector<Record> vector1;

    // Load the vector from the test data.
    for (size_t index = 0; index < database_size; ++index)
    {
        vector1.push_back(database[index]);
    }

    const int key_amount = 20;
    const size_t quantity = vector1.size();
    for (size_t i = 0U; i < quantity; ++i)
    {
      const int amount = vector1[i].amount;
      if (amount > key_amount)
      {
        std::cout << "Found at [" << i << "]: "
                  << amount << ", "
                  << vector1[i].name
                  << "\n";
      }
    }
    return 0;
}

这是输出：

$ ./main.exe
Found at [1]: 100, Luke
Found at [3]: 50, Anakin