c ++将对象从一个类推到另一个类的向量中？

Question

I'm fairly new to c++ programming and was wondering if someone could solve this one issue for me?

I'm going to use some examples for my question here.

Let's say that in my main class I create a Bob object from the Blue class,

Blue Bob("bob", 3);

The Blue class takes a "name" and a size for the vector inside the class.

Now let's introduce another class, Red, which takes four parameters and has three objects,

Red GasPoweredStick("M000", "It never runs out of gas!", 1, 40);
Red Ozone("AFXE", "Filler", 4, 3);
Red Jupiter("KCAT", "Planets make terrible dinner guests", 99, 191919);

I want to add the Red objects to the vector in the Blue class under the Bob object, and then do things with those parameters,

Bob.addItem(GasPoweredStick);
Bob.addItem(Ozone);
Bob.addItem(Jupiter);

which leads to this "addItem" code,

void Blue::addItem(Red&)
{
    Items.push_back(Red());
}

I think my problem is at that above code...and the problem being that the parameter information from the Red objects default to their constructor's values, making them all blank or 0. instead of being filled with the information from the already created objects. The reason as to why I can't solve this myself but got this far is because this is an assignment that I am working on, but my current education with c++ has not mentioned this particular problem. The code is created from template or prior knowledge.

I don't have much experience with c++, but I'm guessing that the addItem function isn't taking in the three created objects but is instead copying the base Red class every time I asked it to push a new object.

I would appreciate any help! I hope I was clear enough. I'll try to clear things up if they need to be.

Answer 1

This line:

Items.push_back(Red());

Your pushing back a newly created Red object using the default constructor. Just pass a reference:

void Blue::addItem(const Red& r)
{
    Items.push_back(r);
}

Answer 2

Your class Red should have a copying constructor and assignment operator:

void Red::Red(const Red& other)
{
(*this) = other;
}

Red& Red::operator=(const Red& other)
{
this->Name = other.Name; 
// TODO: copy other fileds
return (*this);
}