15.java

/* Here, Box defines three constructors to initialize
   the dimensions of a box various ways.
*/
class Box {
    double width;
    double height;
    double depth;
  
    // constructor used when all dimensions specified
    Box(double w, double h, double d) {
      width = w;
      height = h;
      depth = d;
    }
  
    // constructor used when no dimensions specified
    Box() {
      width = -1;  // use -1 to indicate
      height = -1; // an uninitialized
      depth = -1;  // box
    }
  
    // constructor used when cube is created
    Box(double len) {
      width = height = depth = len;
    }
  
    // compute and return volume
    double volume() {
      return width * height * depth;
    }
  }
    
  class OverloadCons {
    public static void main(String args[]) {
      // create boxes using the various constructors
      Box mybox1;
      mybox1 = new Box(10, 20, 15);
      Box mybox2 = new Box();
      Box mycube = new Box(7);
  
      double vol;
  
      // get volume of first box
      vol = mybox1.volume();
      System.out.println("Volume of mybox1 is " + vol);
  
      // get volume of second box
      vol = mybox2.volume();
      System.out.println("Volume of mybox2 is " + vol);
  
      // get volume of cube
      vol = mycube.volume();
      System.out.println("Volume of mycube is " + vol);
    }
  }