The right usage of classes and struct within them

Projects Programming
1

I'm having trouble with a class "Set" I try to use.
The Idea is to be able to access its properties from a public function in Set.

here is a minimal code sample:

#include <FastLED.h>
#define LEDTYPE WS2812B 
#define PL 9                           // LED pin
#define STRIP 134                  //num LED in strip
#define GROUP_NUM 9

CRGB LED[STRIP]; 

void setup() {
  delay(200); 
  FastLED.addLeds<LEDTYPE, PL, GRB>(LED, STRIP);                                                                     
}


class Set {
  public:
    Set() {} //constructor
    struct group {
      byte red, green, blue;
    };
    struct set {
      int setDelay;
      group group[GROUP_NUM];
    };
    //    void sets();
    void GroupPlacement(set);
  private:
    //   void groupPlacement(set);

};

Set set1;

set1.set.setDelay = 50;
set1.set.group[0] = (.100, .0, .0);
set1.group[1] = (0, 100, 0);

void Set::GroupPlacement(set thisset) {
    thisset.group[0] = (1,2,3)
}

void loop() {
set1.GroupPlacement(set1)
}

  1. I'm getting an error that invalid use of struct Set::set. But I initialised set1 of Type Set, what is the mistake here?

  2. what is the correct way to access group[]? is it like I try with group[0] or group[1] (notice the dot)
    error is: "error: no match for 'operator=' (operand types are 'Set::group' and 'int')"

Thanks a bunch!

2

I get an error reporting

'GROUP_NUM' was not declared in this scope
3

right, sorry I must have erased it while taking everything unnecessary. say Its 10. Its not relevant for the questions.

Edited the question.

4

"group" and "set" are type names, not variable names. Further information.

EDIT: You usually never declare types within a class unless they are private to the class.

5

But isn't it more orderly to have a bundle of information in the form of struct, so i can pass it, for example in an array as easy as possible?

What would I do instead to organize passing variables to functions in arrays?

6

Multiple things wrong here:

  • As already pointed out, you only declare struct types group and set. You never define (instantiate) any class members of these types.

  • You instantiate a single object of type Set called set1. Yet, you try to use this variable as an array.

  • You can’t assign values to struct members like you’re trying to do with:

set1.set.group[0] = (.100, .0, .0);
set1.group[1] = (0, 100, 0);

  • The parameter type you’re trying to pass in the definition of GroupPlacement() doesn’t exist. Perhaps you meant “Set thisset”.

  • Regardless of the above, you’re passing by value which means ‘thisset’ is a local variable to GroupPlacement(). Any changes you make to it will have no effect to the argument when the function is called. You need to pass by pointer or reference.

  • Your naming convention is very confusing.

7

You can use a struct in your class, but read reply #3 again. You defined a struct in your class, but you didn't declare an instance of that struct.

8

wildbill:
You can use a struct in your class, but read reply #3 again. You defined a struct in your class, but you didn't declare an instance of that struct.

Sorry to be pedantic, but reverse "define" and "declare" in the above: Difference between Definition and Declaration - GeeksforGeeks