Using an integer indexed list of strings with Arduino

Question

I do have a list of string status messages. Each status message has an individual integer status code assinged to it, like this:

{0, "INITIAL STATE"},
{12, "ERROR INVERTER COMMUNICATION"},
{42, "INITIAL CHARGE"},
{158, "MAINTENANCE CHARGE"},
...

In fact the list has about 200 entries, with 256 being the maximum status code. Now I want to reference the respective string for a statuscode (int) I´m reading from the device. I have been looking at using a struct like this:

typedef struct {
    int Statuscode;
    String StatusString;
} StatusCodes;

and a definition like this:

StatusCodes MyStatuscodes[] = {
    {0, "INITIAL STATE"},
    {12, "ERROR INVERTER COMMUNICATION"},
    {42, "INITIAL CHARGE"},
    {158, "MAINTENANCE CHARGE"},
};

My questions:

• When I get a statuscode of e.g. 12, how do I get to the respective string?
• Is there a better way than using a struct?
• Should I be using a "char *" instead of "String"?
• Ideally I would like to move the list of messages references to a .h file, would that have an impact?

I think there must be an easy solution for this, but being new to C++ I´m struggling with finding a good solution, besides maybe converting to JSON and parsing this.

Answer 1

list has about 200 entries
256 being the max. code.

Is there a better way than using a struct?

Consider an array of const char *.

Consider in some error.cpp file

#incldue "error.h"
const char *StatusString[STATUSSTRING_N] = {
  "INITIAL STATE",
  "UNUSED 1",  
  ...
  "UNUSED 11",  
  "ERROR INVERTER COMMUNICATION"
  ...
};

and in some error.h file

#define STATUSSTRING_N 257
extern const char *StatusString[STATUSSTRING_N];

---

When I get a statuscode of e.g. 12, how do I get to the respective string?

if (statuscode >= 0 && statuscode < STATUSSTRING_N) {
  return StatusString[statuscode];
}

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