Wall.java

// Write a class with the name Wall. The class needs two fields (instance variables) with name width and height of type double.  

// The class needs to have two constructors. The first constructor does not have any parameters (no-arg constructor). The second constructor has parameters width and height of type double and it needs to initialize the fields. In case the width is less than 0 it needs to set the width field value to 0, in case the height parameter is less than 0 it needs to set the height field value to 0.  

// Write the following methods (instance methods):

// Method named getWidth without any parameters, it needs to return the value of width field.
// Method named getHeight without any parameters, it needs to return the value of height field.
// Method named setWidth with one parameter of type double, it needs to set the value of the width field. If the parameter is less than 0 it needs to set the width field value to 0.
// Method named setHeight with one parameter of type double, it needs to set the value of the height field. If the parameter is less than 0 it needs to set the height field value to 0.
// Method named getArea without any parameters, it needs to return the area of the wall.
//   TEST EXAMPLE  

// → TEST CODE:  

// 1 Wall wall = new Wall(5,4);

// 2 System.out.println("area= " + wall.getArea());

// 3wall.setHeight(-1.5);

// 4 System.out.println("width= " + wall.getWidth());

// 5 System.out.println("height= " + wall.getHeight());

// 6 System.out.println("area= " + wall.getArea());

//  OUTPUT:  

// area= 20.0

// width= 5.0

// height= 0.0

// area= 0.0


public class Wall
{
    private double width;
    private double height;

    public Wall ()
    {
    }

    public Wall (double width, double height)
    {
        if (width < 0)
        {
	        width = 0;
        }

        if (height < 0)
        {
	        height = 0;
        }
    
        this.width = width;
        this.height = height;
    }
  
    public double getWidth ()
    {
        return width;
    }

    public double getHeight ()
    {
        return height;
    }

    public void setWidth (double width)
    {
        if (width < 0)
        {
	        width = 0;
        }
        this.width = width;
    }

    public void setHeight (double height)
    {
        if (height < 0)
        {
	        height = 0;
        }
        this.height = height;
    }

    public double getArea ()
    {
        return getWidth () * getHeight ();
    }

    public static void main (String[]args)
    {
        Wall wall = new Wall (5, 4);
        System.out.println ("area= " + wall.getArea ());
        wall.setHeight (-1.5);
        System.out.println ("width=" + wall.getWidth ());
        System.out.println ("height= " + wall.getHeight ());
        System.out.println ("area= " + wall.getArea ());
    }
}