我几乎是C ++的新手。我开设了一个学生班。首先，当我返回标记的媒体时，它不是浮点值。例如：如果我输入5和10，它将返回7而不是7.5。
其次，当我想用函数disp（）显示名称和媒体时，它不起作用。
有人可以帮忙吗？
谢谢
#include <iostream>
using namespace std;
class student{
public:
string name;
int mark1, mark2;
float calc_media(){
float media = (mark1 + mark2)/2;
return media;
}
void disp(){
cout << "Student:" << name << endl;
cout << "media:"<< calc_media() << endl;
}
};
int main (){
student peter;
cout <<"name:" ;
cin>>peter.name;
cout <<"mark1:" ;
cin>>peter.mark1;
cout <<"mark2:" ;
cin>>peter.mark2;
cout <<"ALL:" << peter.disp();
return 0;
}
编辑： 我也知道我可以做这样的事情：
我已经删除了该函数的功能，并且已经将该类写出了，但是它不起作用。
#include <iostream>
using namespace std;
class student{
public:
string name;
int mark1, mark2;
float calc_media(int, int);
void disp(){
cout << "Student:" << name << endl;
cout << "Media:"<< calc_media(int, int) << endl;
}
};
student::float calc_media(int x, int y){
float media = (x + y)/2.0;
return media;
}
int main (){
student peter;
cout <<"name:" ;
cin>>peter.name;
cout <<"mark1:" ;
cin>>peter.mark1;
cout <<"mark2:" ;
cin>>peter.mark2;
cout <<"media:" << peter.calc_media(peter.mark1, peter.mark2) << endl << endl;
peter.disp();
return 0;
}
Here what you are doing is called integer division, both variables
mark1andmark2are integers and so is2thus, it will provide you an integer.Try replacing
2with2.0to achieve floating point division.And as your
dispfunction is not returning something you need not tocoutit. You can do this,在此表达式中：
you are doing integer division, since both the variables and the literal are
inttypes. You could simply do:相反，要进行浮点除法。
To get
dispto work, note that it doesn't return anything, so you need to simply call it like this:and not pass the result of this function to
cout.Alternatively, instead of
disp, you can overload theoperator<<like this:然后像这样使用它：