对象数组，在主函数运行时会出现0，要怎么修改可以去掉0

 #include<iostream>
using namespace std;

class student
{
private:
    int number;//学号
    int grade;//成绩
public:
    student(int, int);
    int showinform();
};

student::student(int a, int b)
{
    number = a;
    grade = b;
}


int student::showinform()
{
    cout << "学号:" << number << "   " << "成绩:" << grade << endl;
    return 0;
}
void main()
{
    student a[3] = {
        student(1, 100),
        student(2, 98),
        student(3, 96)
    };
    cout << a[0].showinform() << endl;
    cout << a[1].showinform() << endl;
    cout << a[2].showinform() << endl;

}

因为showinform定义成int型， 且返回值为0。
修改后的代码如下：

#include<iostream>
using namespace std;

class student
{
private:
    int number;//学号
    int grade;//成绩
public:
    student(int, int);
    void showinform();
};

student::student(int a, int b)
{
    number = a;
    grade = b;
}


void student::showinform()
{
    cout << "学号:" << number << "   " << "成绩:" << grade << endl;
    //return 0;
}
void main()
{
    student a[3] = {
        student(1, 100),
        student(2, 98),
        student(3, 96)
    };
    a[0].showinform();
    a[1].showinform();
    a[2].showinform();
}