C++ 关于bool函数的一个小问题

Question

/*我写的这个程序是可以运行的，但我不清楚我写的bool函数是否符合题意，因为输入不符值后输出的是三串长长的数字...麻烦大神们帮我看一下需不需要改正~可以的话，可以详细讲讲bool函数的作用和用法吗？对这个函数还是不太熟悉...*/

    class CDate{
    public:
            bool set(unsigned int year,unsigned int month,unsigned day);
            void print();
    private:
            unsigned int m_nYear;
            unsigned int m_nMonth;
            unsigned int m_nDay;
    };
    bool CDate::set(unsigned int year,unsigned int month,unsigned day)
    {
            if((month>12)||(day>31))
                    return false;
            else
            m_nYear=year;
            m_nMonth=month;
            m_nDay=day;
            return true;
    }
    void CDate::print()
    {
            cout<<m_nYear<<"　"<<m_nMonth<<" "<<m_nDay;
    }
    int main(int argc, char* argv[])
    {
            CDate today;
            today.set(2016,44,19);
            today.print();
        system("pause");
            return 0;
    }

Answer 1

1.输出一串很长的数是因为你没有初始化过，帮楼主加了一个构造函数
2.set函数里else分支应该加上括号，虽然加不加结果是一样的
3.既然set有返回值，就应该在main函数里接收该返回值，并且对于不同的返回值进行一些相应的处理
4.bool参考：http://www.cnblogs.com/JarvisChu/archive/2011/07/03/2752472.html

#include<iostream>
using namespace std;
class CDate{
public:
    CDate():m_nYear(0),m_nMonth(0),m_nDay(0){}
    bool set(unsigned int year,unsigned int month,unsigned day);
    void print();
private:
    unsigned int m_nYear;
    unsigned int m_nMonth;
    unsigned int m_nDay;
};
bool CDate::set(unsigned int year,unsigned int month,unsigned day)
{
    if((month>12)||(day>31))
        return false;
    else
    {
        m_nYear=year;
        m_nMonth=month;
        m_nDay=day;
    }

    return true;
}
void CDate::print()
{
    cout<<m_nYear<<"　"<<m_nMonth<<" "<<m_nDay;
}
int main(int argc, char* argv[])
{
    CDate today;
    bool set_res = today.set(2016,44,19);
    if(!set_res)
        cout << "set error" << endl;
    today.print();
    system("pause");
    return 0;
}