I'd like to know if there's any possibility to create a constructor in C++ which uses for example float but this float isn't necessary. I mean:
Constructor:
Fruit::Fruit(float weight)
{
weight = 1;
this->setWeight(weight);
}
I need to do something like that using one constructor:
Fruit pear = Fruit(5); - gives a pear with weight 5
Fruit strawberry = Fruit(); - gives a strawberry with default weight 1
Yes, this can be done by specifying the value with a = in the argument list:
Fruit::Fruit(float weight = 1)
{
this->setWeight(weight);
}
Use in-class initialization, which can significantly clean up code:
class Fruit {
public:
Fruit() = default;
Fruit(float weight) : weight_{weight} {}
// ... other members
private:
float weight_ { 1.0f };
};
This way, a default weight of '1' is automatically created if the default c'tor is called. This has the benefit of significantly cleaning up initialization lists in constructors. Consider what would happen if you had many class members that are default-initialized to garbage values (i.e. any of the built-in types). Then you would have to explicitly initialize them in the c'tor initializer lists, which gets cumbersome. With in-class initialization, you can do this at the member declaration site.
