'='标记/对象​​计数器变量之前的声明中的qualified-id

Question

我正在尝试计算有多少个实例或类mole2，并将该数字存储在名为mole_count的公共静态变量中。

mole2.h

#ifndef mole2_h
#define mole2_h

#include "Arduino.h"
class mole2 {
  public:
    mole2(int input, int output);
    void popUp();
    void popdown();
    boolean moleBrainThinkPopUpNow();
    void setUpTimer(int up_timer);
    boolean didMoleGetHit();
    void setRecoveryTimer(int recovery_timer);
    void decrementRecoveryTimer();
    boolean dosePlayerMistMole();
    void moleReset();

    int input, output;
    static int mole_count;
    static int odds_of_poping;

  private:
    boolean _is_popped = false;

    int _up_timer = 0;
    int _recovery_timer = 0;

};
#endif

mole2.cpp

#include "Arduino.h"
#include "mole2.h"

int mole2::odds_of_poping = 10;

mole2::mole2(int input, int output) {
  input = input;
  output = output;
  int mole2::mole_count = mole2::mole_count + 1;
  pinMode(input, INPUT);
  pinMode(output, OUTPUT);
}

void mole2::popUp() {
  _is_popped = true;
  digitalWrite(input, HIGH);
}

void mole2::popdown() {
  _is_popped = false;
  digitalWrite(input, LOW);
}


boolean mole2::moleBrainThinkPopUpNow() {
  if (_recovery_timer == 0 &&  _is_popped == false && rand() % odds_of_poping == 1) {
  popUp();
    return true;
  }
  else {
    return false;
  }
}

void mole2::setUpTimer(int up_timer) {
  _up_timer = up_timer;
}

boolean mole2::didMoleGetHit() {
  if (_is_popped == true && digitalRead(input) == HIGH) {
    popdown();
    _up_timer = 0;
    return true;
  }
  else {
    return false;
  }
}

void mole2::setRecoveryTimer(int recovery_timer) {
  _recovery_timer = recovery_timer;
}

void mole2::decrementRecoveryTimer() {
  if (_recovery_timer > 0) {
    _recovery_timer--;
  }
}

boolean mole2::dosePlayerMistMole() {
  if (_is_popped == true && _up_timer > 0) {
    _up_timer--;
  }
  if (_is_popped == true && _up_timer == 0) {
    popdown();
    return true;
  }
  else {
    return false;
  }
}

void mole2::moleReset() {
  popdown();
  _up_timer = 0;
  _recovery_timer = 0;
}

FullError

Arduino: 1.6.12 (Windows 7), Board: "Arduino/Genuino Uno"

C:\Users\Strings\Documents\Arduino\libraries\mole2\mole2.cpp: In constructor 'mole2::mole2(int, int)':

C:\Users\Strings\Documents\Arduino\libraries\mole2\mole2.cpp:9:25: error: qualified-id in declaration before '=' token

   int mole2::mole_count = mole2::mole_count + 1;

                         ^

exit status 1
Error compiling for board Arduino/Genuino Uno.

This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.

Answer 1

你必须做与odds_of_poping相同的事情：

定义：

int mole2::mole_count = 0; // initialization can be ommited as static variables are initialized to the default value

以后只需增加：++mole_count;

Answer 2

int mole2::mole_count已经定义。这是试图制作另一个int mole2::mole_count。丢失int并分配给预先存在的变量。

您还需要为mole_count分配存储空间并对其进行初始化。放置

int mole2::mole_count = 0; // replace 0 if starting with more than 0 mole2s

在某处

int mole2::odds_of_poping = 10;

in mole2.cpp

还要注意

input = input;
output = output;

编译器不知道您是否要使用传递的参数input或类input，因此它将选择最接近的定义input，参数，在=的两侧。避免在同一时间重复使用相同的变量名称。

这可以通过明确说明来解决

this->input = input;
this->output = output;

或者（我最喜欢的！）使用member initializer list

mole2::mole2(int input, int output): input(input), output(output) {

但是为了防止其他混乱，你仍然不应该重复这些名字。