No-argument Constructor

Examine the following proposed constructor for Movie:

// proposed constructor
public Movie( String ttl, int lngth, String dir, String rtng )
{
  title = ttl;       // do what the parent's constuctor does.
  length = lngth;  
  avail = true;
  
  director = dir; rating = rtng;
}

It looks like there is no need to invoke the parent class's constructor since all variables are initialized in this one. However a constructor from the parent class is always invoked even if you don't explicity ask for it. The Java compiler regards the above code as "shorthand" for this:

// proposed constructor
public Movie( String ttl, int lngth, String dir, String rtng )
{
  super();           // invoke the parent's no-argument constructor
  title = ttl;       // do what the parent's constuctor does.
  length = lngth;  
  avail = true;
  
  director = dir; rating = rtng;
}

As always, super() comes first, even if you don't write it in. If the parent does not have a no-argument constructor, then using this "shorthand" causes a syntax error.

In our program the class definition for Video (the superclass) lacks a no-argument constructor. The proposed constructor (above) calls for such a constructor so it would cause a syntax error.