friend className function();

Friend functions have access to the private member data of the class they are contained within. This allows for the user to have a function separate from the class, but still interact with it.

• For operator overloads, friends may need to be used

className objectName = function(param);

We can call the friend function with the above syntax. Notice that no dot operator is used, this is because it is not explicitly part of the object, rather a separate function.

We also do not need to use scope resolution in order to define the friend function, within the implementation file.

Conversion Constructors

- used to facilitate automatic type conversion - conversion constructors have one parameter, and can be invoked explicitly or implicitly

int main(){
	Fraction f = 9;  
}

The definition of the conversion constructor will define what 9 means in this context

1. Conversion constructors support implicit type conversion.
2. Getters are typically marked as const

Using Const

- will not change state of object - can only call other const functions - should be used for getters and display functions - Only the constructor of a const object can change the state

Destructors

- work just like constructors, but are implicitly called when the object falls out of scope - Destructors are commonly used to cleanup shared resources