I need to create a box class that will create three types of boxes, with 0, 1,
or 3 parameters.  I have written some code but I don't understand what is
meant by 0, 1, or 3, parameters. I am having problems writing the
constructors for the parameters because I don't understand what they are
supposed to do.  Any help clarifying this would be greatly appreciated.
After I write the constructors where in the code would I place them?

Thanks

public class box()
  {
     this.length = 1.0;
     this.width = 1.0;
     this.height = 1.0;
  }

// Method to determine volume

     public void calVolume(double vol)
   {
     vol = length * width * height;
   }

// Method for returning volume
   public double getVol()
   {
      return vol;
   }

//Method to determine Area
     public void calArea(double area)
   {
     
     area = 2*length*width + 2*length*height + 2*width*height;
   }

//Return Area
public double getArea()
    {
       return area;
    }

These are the instructions for the assignment

Create a Box class. The program should be able to create three types of boxes,
with 0, 1, or 3 parameters. If the box is a cube you should only have to
provide the length of one side. You should also be able to specify the length,
width, and height of the box. You should also be able to create a box with
zero dimensions, using default values. You should be able to perform the
following calculations on your box: area and volume. Furthermore, you should
be able to make your box larger and smaller in two different ways.

Specify by how much larger (multiplier) you would like to enlarge each
dimension of the object. For example, makeLarger(2) would multiply the length,
width, and height of the box by 2.
Specify the specific amount you would like to add to each dimension of the
box. For example, makeLarger(1, 3, 5) would add 1 to the length, 3 to the
width, and 5 to the height of the box.
Be sure to include methods for the following tasks:

Constructors (three)
Calculate and return the volume
Calculate and return the area
Enlarge the box (two ways)
Output the dimensions
Demonstrate that your program works properly. Display all results to two
decimal places.