一、

//构造函数
struct student{
    string name;
    int age;
    student(){}
    student(string n,int a):name(n),age(a){}
};
int main(){
    student mike=student("Mike",20);
    cout<<mike.name<<","<<mike.age<<endl;
    student who;
    cout<<who.name<<","<<who.age<<endl;
    return 0;
}

二、删去student(){}

会导致如果不定义初始化的值，就无法创建新的struct。

但其实原来是可以的。

//构造函数
struct student{
    string name;
    int age;
    //student(){}
    //student(string n,int a):name(n),age(a){}
};
int main(){
    //student mike=student("Mike",20);
    //cout<<mike.name<<","<<mike.age<<endl;
    student who;
    cout<<who.name<<","<<who.age<<endl;
    return 0;
}