Expert C Programming

Write the Method Bodies

Write similar bodies for slice() and juice() for the Fruit class. Copy the body of
peel to start with.

1. In a real system, these methods would presumably operate a robot arm to
   carry out the desired fruit preparation. In this training exercise, just make
   each method print out the fact that it has been invoked.


2. Give these methods likely parameters and return types. For example,
   slice() should take an integer parameter indicating the desired number of
   slices, juice() should return a float value representing the number of cc's
   of juice obtained, and so on. The prototypes in the class definition will have
   to match the function definitions, of course.


3. Try accessing data in the private part of the class, from inside a method and
   then from outside.

How to Call a Method

Look at the interesting way to call a function within a class. You have to prefix it with the instance, or
class variable, you want it to operate on.

Fruit melon, orange, banana;

main() {

melon.slice();

orange.juice();

return 0;

}

Then the object does that operation on itself. It's quite similar to some predefined operators; when we
write i++ we are saying "take the i object and do the post-increment operation on it." Invoking a
member function on a class object is equivalent to the "sending a message to that object" terminology
that other object-oriented languages use.

Every method has a this pointer parameter implicitly passed to it, allowing an object to refer to itself
inside a method. Note how the explicit use of the this pointer can be omitted when inside a member
function, and it is assumed.

class Fruit { public: void peel();