what's the difference?

Question

So if we delete the keyword 'operator+' what's the difference? If you pass Box a and Box b as parameters then the method will still have access to a.Height, b.Height and so on and we will create the new Box object the same way... Right? or not? (and why)

Answer 1

You are right, but miss-interpreted what operator overloading does.

Lets say I didn't overload the operator:
Box add(Box a, Box2 b){
return a.getArea() + b.getArea();
}
// For this example, I'm just adding areas

This is perfectly acceptable.
Now if I want to add them, I can do:

add(Box1, Box2);

Where I'm only adding areas.

However, sometimes it may feel better to use + for addition instead of having to write add.
In that case, you use "operator" to indicate you will be overloading an operator. Followed by the operator itself. "+".
That way, I can write:
Box1 + Box2.
To add the areas.

This is entirely optional of course, which is why some languages don't support it (Like Java). But can be a nice thing for the programmer.

It's essentially nicer for arithmetic.
Lets say I had 2 boxes name a and b.

((a + b * 5) / 3)^2

Would that be easier to read than this?

pow((divide(multiply(add(a, b), 5), 3), 2);

It helps make it like a data-type.