6. Controlling Object Creation

public class Planet
{
    int distance;   // distance from star
    int satellites; // # of satellites
    double mass;    // the mass

    public Planet() // default constructor
    {
        this.distance = 0;
        this.satellites = 0;
        this.mass = 0;
    }

public class GasGiant extends Planet
{
    public GasGiant()
    {
        // Explicit call to
        // base constructor:
        super();
    }
}

    public Planet(int distance, int satellites, double mass)
    {
        this.distance = distance;
        this.satellites = satellites;
        this.mass = mass;
    }
}