C ++：我无法启动我的课程，我在这个范围错误中未声明课程

Question

I'm using netbeans with gcc compiler and when I try to declare an object of my class, and run the code I get the class was not delclared in this scope error, this is my code in main.cpp:

#include <cstdlib>
#include <iostream>
#include <cstring>

using namespace std;

int main() {
    Clock r;
    r.processH();

    return 0;
}

class Clock {

private:
    int h, m, s;
    char conv[];

    Clock() {
        h = 0;
        m = 0;
        s = 0;
        conv[10] = {};
    }

public:

    void processH() {
        int r =0; 
        while(r <= 2){
            conv[r] = 'I';
            if(conv == "III") {
                conv[0] = 'V';
                conv[1] = 'I';
                r++;
                break;
            }
            r++;
        }
        cout<< r;
    }

};

What am I doing wrong? I'm not an experienced OOP programmer.

Answer 1

First, you should declare the class before you use it's name. In your case it should be above the main function.

Second, you declared Reloj function with no return type, which is illegal.

The correct code may look like this:

#include <cstdlib>
#include <iostream>
#include <cstring>

using namespace std;

class Clock {
private:
    int h, m, s;
    char conv[];

    void Reloj() {
        h = 0;
        m = 0;
        s = 0;
        conv[10] = {};
    }

public:

    void processH(int ent) {
        int r =0; 
        while(r <= 2) {
            conv[r] = 'I';
            if(conv == "III") {
                conv[0] = 'V';
                conv[1] = 'I';
                r++;
                break;
            }
            r++;
        }
        cout<< r;
    }
};


int main() {
    Clock r;
    r.processH(5);
    return 0;
}

Answer 2

Just a complement to Sergey's answer : You could also forward declare the class. Just add the line

class Clock;

before your main function to tell the compiler that the class exists.