Why can I only access public object instances within their own file and not outside?

[mursalahmed78]

I am learning about C++ as I go, so bear with me.

In my Arduino project, I have a class declaration at the start of one of my files, Parser.h. In Parser.cpp, I set the variables of the struct declared in Parser.h by iterating through a C string. I have tested this function and I know it performs as intended.

However, the issue begins when I try to refer to Parser.cocktail's variables outside of the Parser.h and Parser.cpp scopes. I have tried a print statement in my main.ino file, as well as in a separate library I made that is also #includeing Parser.h, and neither of them output anything. It's as if they don't see the variables if they're outside the scope, even though they are public.

Parser.h

#ifndef PARSER_H_
#define PARSER_H_
#include <stdio.h>
#include <Arduino.h>

class parser
{
public:
    struct Drink
    {
        char name0[30];
        char name1[30];
        char name2[30];
    };
    Drink cocktail;
    char buffer[250];
    
    void getRecipe();
};

static parser Parser; 

#endif

Parser.cpp

#include "parser.h"
#include <stdio.h>
#include <string.h>
using namespace std;

void parser::getRecipe()
{
    char *p;
    uint8_t n = 0;
    uint8_t iter = 0;
    const char strr[14] = "Hello World !";
    strcpy(buffer, strr);
    for (p = strtok(buffer, " "); p != NULL; p = strtok(NULL, " "))
    {
        if (iter == 0)
        {
            strcpy(Parser.cocktail.name0, p);
            iter++;
        }
        else if (iter == 1)
        {
            strcpy(Parser.cocktail.name1, p);
            iter++;
        }
        else if (iter == 2)
        {
            strcpy(Parser.cocktail.name2, p);
            iter++;
        }
    }
    Serial.println(Parser.cocktail.name0);
    Serial.println(Parser.cocktail.name1);
    Serial.println(Parser.cocktail.name2);
}

main.ino

#include <Arduino.h>
#include <Parser.h>

void setup()
{
  Serial.begin(9600);
  while (!Serial)
  {
    continue;
  }
  Parser.getRecipe();
  Serial.println(Parser.cocktail.name0);
  Serial.println(Parser.cocktail.name1);
  Serial.println(Parser.cocktail.name2);
}

void loop()
{
  
}

This is the Serial output I am getting: site

Hello
World
!

However it should look like:

Hello
World
!
Hello
World
!

Because Serial.println is called 3 times both in main.ino as well as Parser.cpp. The output is coming from Parser.cpp exclusively.

[Juraj]

put parser Parser; into the cpp and add extern parser Parser; into .h. this way you will have a single global object of type parser.

now you have two objects one in cpp and one in ino, because both files have static parser Parser; (#include is replaced by the content of the .h)

[MicroBahner]

Yes, this line is our problem:

static parser Parser; 

You get a local instance in each file where you include Parser.h. But you should have only one global instance.