How to Get enum item name from its value

Question

I declared a enum type as this,

enum WeekEnum { Mon = 0; Tue = 1; Wed = 2; Thu = 3; Fri = 4; Sat = 5; Sun = 6; }; 

How can I get the item name "Mon, Tue, etc" when I already have the item value "0, 1, etc."

I already have a function as this

Log(Today is "2", enjoy! );

And now I want the output below

Today is Wed, enjoy

Answer 1

You can't directly, enum in C++ are not like Java enums.

The usual approach is to create a std::map<WeekEnum,std::string>.

std::map<WeekEnum,std::string> m; m[Mon] = "Monday"; //... m[Sun] = "Sunday"; 

Answer 2

Here is another neat trick to define enum using X Macro:

#include <iostream>  #define WEEK_DAYS \ X(MON, "Monday", true) \ X(TUE, "Tuesday", true) \ X(WED, "Wednesday", true) \ X(THU, "Thursday", true) \ X(FRI, "Friday", true) \ X(SAT, "Saturday", false) \ X(SUN, "Sunday", false)  #define X(day, name, workday) day, enum WeekDay : size_t {     WEEK_DAYS }; #undef X  #define X(day, name, workday) name, char const *weekday_name[] = {     WEEK_DAYS }; #undef X  #define X(day, name, workday) workday, bool weekday_workday[] {     WEEK_DAYS }; #undef X  int main() {     std::cout << "Enum value: " << WeekDay::THU << std::endl;     std::cout << "Name string: " << weekday_name[WeekDay::THU] << std::endl;     std::cout << std::boolalpha << "Work day: " << weekday_workday[WeekDay::THU] << std::endl;      WeekDay wd = SUN;     std::cout << "Enum value: " << wd << std::endl;     std::cout << "Name string: " << weekday_name[wd] << std::endl;     std::cout << std::boolalpha << "Work day: " << weekday_workday[wd] << std::endl;      return 0; } 

Live Demo: https://ideone.com/bPAVTM

Outputs:

Enum value: 3 Name string: Thursday Work day: true Enum value: 6 Name string: Sunday Work day: false