constructor does not run

问题

I do not understand because when you create an object of the "Users" class not the message is printed containing the constructor.

class users
{
public:
    users();
private:
    int i;
};
users::users ()
{
    cout<<"hello world";
}
int main ()
{
    users users1();
    return 0;
}

回答1:

users users1();

doesn't declare an object of the users class, it declares a function that takes no arguments and returns an object of the users class. To declare an object, use:

users users1;

回答2:

class users
{
public:
    users();
private:
    int i;
};
users::users ()
{
    cout<<"hello world";
}
int main ()
{
    users users1; // either you use this
    users* user2 = new users(); // or you do this
    return 0;
}

This worked fine for me. see here

来源：https://stackoverflow.com/questions/27161295/constructor-does-not-run