动态获取结构中成员的值

Question

Here there is a structure:

struct date
 {
  int day;
  int month;
  int year;
 }frmt;

A structure is initialized and members are assigned values. Now, I want to get value of a member using dynamic variable.

Generally we use frmt.day to get value of that member. Now let std::string str1="day"; How can i get member value using str1? Can I use str1.c_str() ??

Answer 1

You can use std::map<std::string, int> or std::unordered_map<std::string, int> for you simple struct in the example. In this case you should in all places in your code replace frmt.day with frmt["day"] and etc. Thus you can call frmt[str1] .

If a struct has members of various types, you could use std::variant instead of int (since C++17).