class Button
{
private:
  byte _pin = 0;
  byte _state = 0;
  float _time_click = 50.0f;
  float _time_long_click = 2000.0f;

public:
  Button()
  {

  };

  Button(byte pin)
  {
    _pin = pin;
    pinMode(_pin, INPUT);
    digitalWrite(_pin, LOW);
  }

  void SetData(byte pin)
  {
    _pin = pin;
    pinMode(_pin, INPUT);
    digitalWrite(_pin, LOW);
  }

  bool CheckClick()
  {
    int dig = digitalRead(_pin);
    Serial.println(dig);
    if (dig > 0)
    {
      Serial.print("Button click ");
      Serial.println(_pin);
      if (_state == 0)
      {
        _state = 1;
        return true;
      }
    }

    return false;
  }
};

Button Buttons[4];

void setup() 
{
  // put your setup code here, to run once:
  Serial.begin(9600);
  Buttons[0].SetData(2);
  Buttons[1].SetData(3);
  Buttons[2].SetData(4);
  Buttons[3].SetData(5);
}

void loop() 
{
  delay(1000);
  // put your main code here, to run repeatedly:
  for(int id = 0; id < 4; id++)
  {
    if(Buttons[id].CheckClick())
      OnButtonClick(id);
  }
}

void OnButtonClick(byte id)
{
  Serial.print("ID Button click = ");
  Serial.println(id);
}