如何调用数组中的值并更改数组中的值？

Question

class DataStorage{
                        // 0 1 2 3 4        5 6 7 8
string Data[20][4]={{"Wee","50","1","First"},{"Wee","22","2","First"},
                        // 9 10 11 12       13 14 15 16
                    {"Jason","26","3","First"},{"Krappa","12","4","First"},
                        // 17 18 19 20      21 22 23 24
                    {" "," ","5","First"},{" "," ","6","Economy"},
                        //25 26 27 28       29 30 31 32
                    {"Kappa","15","7","Economy"},{"Eraser","17","8","Economy"},
                        //33 34 35 36       37 38 39 40
                    {" "," ","9","Economy"},{"Morty"," ","10","Economy"},
                        //41 42 43 44       45 46 47 48
                    {"Rick"," ","11","Economy"},{"Amanda","10","12","Economy"},
                        //49 50 51 52       53 54 55 56
                    {"Lee","","13","Economy"},{"MingLee"," ","14","Economy"},
                        //57 58 59 60       61 62 63 64
                    {"Beauty"," ","15","Economy"},{"S4head"," ","16","Economy"},
                        //65 66 67 68       69 70 71 72
                    {"Ivan"," ","17","Economy"},{"Dex"," ","18","Economy"},
                        //73 74 75 76       77 78 79 80
                    {"Chua"," ","19","Economy"},{"Haha"," ","20","Economy"},};
};
int main(){

}

如何调用数组中的值并更改数组中的值？ 我是否需要做一些函数来从输入中获取值，并将其传递给类中的变量，然后将其设置为数组？

Answer 1

我不确定您在说什么时要问的问题How do I call the value in array and change the value in array? 但我想您是在问如何更改数组元素的值。

要修改数组元素，可以将数组的索引分配给将数组元素更改为的元素。 但是，请记住，C ++数组是0索引数组，这意味着当您开始将其元素计数为0时。例如，以下代码修改了索引5处的元素。 实时预览

#include <iostream>

int array[10] = {1, 5, 33, 7, -23, 2, 8, 54, 19, 2};

int main() {
  std::cout << array[5] << std::endl;

  array[5] = 100; // Set the value of the element at index 5 to 100

  std::cout << array[5] << std::endl;

  return 0;
}

Answer 2

如果要将Data作为DataStorage的类成员，则必须在成员初始化列表中对其进行初始化。 我也强烈建议对裸数组使用抽象，例如std::array 。 这允许通过at()函数使用边界检查访问。 然后，您可以访问Data并更改其内容。

#include <array>
#include <iostream>
#include <string>

class DataStorage
{
public:
    std::array<std::array<std::string,4>,20> Data;
    DataStorage() : Data({{
                {{"Wee","50","1","First"}},
                {{"Wee","22","2","First"}},
                {{"Jason","26","3","First"}},
                {{"Krappa","12","4","First"}},
                {{" "," ","5","First"}},
                {{" "," ","6","Economy"}},
                {{"Kappa","15","7","Economy"}},
                {{"Eraser","17","8","Economy"}},
                {{" "," ","9","Economy"}},
                {{"Morty"," ","10","Economy"}},
                {{"Rick"," ","11","Economy"}},
                {{"Amanda","10","12","Economy"}},
                {{"Lee","","13","Economy"}},
                {{"MingLee"," ","14","Economy"}},
                {{"Beauty"," ","15","Economy"}},
                {{"S4head"," ","16","Economy"}},
                {{"Ivan"," ","17","Economy"}},
                {{"Dex"," ","18","Economy"}},
                {{"Chua"," ","19","Economy"}},
                {{"Haha"," ","20","Economy"}}
            }}) {}
};

int main()
{
    DataStorage d;
    std::cout << d.Data.at(10).at(2) << '\n'; // prints 11
    d.Data.at(10).at(2) = "1729";
    std::cout << d.Data.at(10).at(2) << '\n'; // prints 1729
}