相关疑难解决方法(0)

我已经告诉别人,编写using namespace std;代码是错误的,我应该用std::cout和std::cin直接代替.

为什么被using namespace std;认为是不好的做法？是低效还是冒着声明模糊变量(与名称std空间中的函数具有相同名称的变量)的风险？它会影响性能吗？

我在练习施工人员.下面是我练习的代码,但得到的错误是"参考距离模糊不清"我无法识别我的错误,请帮助我.我一直在尝试.

#include <iostream>
#include <conio.h>
using namespace std;

//distance

class distance
{
public:
    distance(int met, int cen);
    distance(int met);
    void display();

private:
    int meters;
    int centimeters;

};


distance::distance(int met, int cen){
cout<<"Object have been initialized and assigned the values"<<endl;
meters=met;
centimeters=cen;

}
distance::distance(int met){
meters=met;
cout<<"One member has been initialized "<<endl;
cout<<"Please enter the distance in centimeters"<<endl;
cin>>centimeters;

}

void distance::display(){
cout<<"The distance in centimeters is "<<centimeters<<endl;
cout<<"The distance in meters is "<<meters<<endl;

}   
int main(){
//explicit call
distance a=distance(10,20); …