C ++ / Arduino Array in class

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C ++ / Arduino Array in class

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#1 by (2 votes)

3

I have a problem in using an array of pointers, I need to create an array with pointers that refer to an integer value of each object of another class.

Example:

arrayDePonteiros[0] = objeto.int;

In case this array is inside a class and as it will be only a reference it will be static, so I can use this array to refer to the value of each object of the other class, which will be recorded in an eeprom in the future. When I read the value in eeprom I can use the pointer to pass the eeprom value to the object variable.

My current code is:

class Scenario {

public:
int byteInicial; // byte da eeprom
static int* link[6]; // atual array de ponteiros



Scenario(int byteI) // construtor da classe
{ 

byteInicial = byteI;
link[0] = &led1.fade;
}

In this case I get the error: undefined reference to 'Scenario :: link'. I've already tried using

Scenario::Scenario link [0] = &led1.fade;

But I get the error trying to use it anyway, either by printing on the serial or trying to write to eeprom. What would be the right way to do this?

c++ classes arduino ponteiro array

asked by anonymous 16.08.2014 / 22:51

1 answer

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score 2 · Answer 1

This problem occurs because variables qualified as static in classes / structures must be defined outside the class and declared within it. So, somewhere in your cpp file that is associated with this class you must declare the array.

// Arquivo .h
class Scenario {
public:
    int byteInicial; // byte da eeprom
    static int* link[6]; // atual array de ponteiros

    Scenario(int byteI) // construtor da classe
    { 
        byteInicial = byteI;
        link[0] = &led1.fade;
    }
    // ...
};

// Arquivo .cpp
int * Scenario::link[6];

As for your code, do you really want to save only pointer to 1 object at a time as you are doing? In that case would not it be better to use a normal pointer instead of an array of pointers? These are questions that I think you should ask yourself.