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Thread: Problem in Class, Displaying only one last change in value!

  1. #1
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    Default Problem in Class, Displaying only one last change in value!

    Okay so I have a rectangle class having the default values for the rectangle'd height, width and color and area. Everything is working fine when I test them in my Test Class except the color.
    Suppose I create two rectangle objects in test class, r1 and r2, I can find the area with different values easily and print them out, but for color, its only showing me the color of r2, If I remove object r2 and keep r1 only then I can see the color name of my object r1; otherwise its showing me the color of r2 in both r1 and r2 when I print them out. Code and output is below

    Rectangle Class
    public class Rectangle {
    private double width = 1;
    private double height = 1;
    private static String color = "white";
     
     
                    public Rectangle (double newWidth, double newHeight, String newColor ) {
                    setWidth(newWidth);
                    setHeight(newHeight);
                    setColor(newColor);
                    }
     
                    public double getWidth ( ) { 
                    return width;  
                    }  
     
                    public void setWidth ( double newWidth ) {
                      if (newWidth <= 0) {
                           System.out.println("Fatal error");
                           System.exit(0);
                      }
                      else {
                         width = newWidth;
                      }
                     }
     
     
                    public double getHeight ( ) { 
                     return height;
                                }       
     
     
                    public void setHeight ( double newHeight ) { 
                          if (newHeight <= 0) {
                            System.out.println("Fatal error");
                            System.exit(0);
                           }
                           else {
                            height = newHeight;
                          }
                    }
     
                   public String getColor ( ) {
                    return color;
                    }
     
                   public void setColor ( String newColor ) {
                     color = newColor;
                    }
     
     
                    public double findArea (  ) {
                    double area = width * height;  
     
                    return area;
                    }
                    public String toString ( ) { 
                    return ("Deafult height " + height + "Default width " + width + "Default color " + color);
                    }
     
    }


    Test Class
    public class TestClass {
     
    public static void main(String[] args){
                //invoking parameterized constructor
                Rectangle r1 = new Rectangle(7, 6, "red");        
                double area1 = r1.findArea();
     
     
                Rectangle r2 = new Rectangle(9, 5, "yellow");
                double area2 = r2.findArea();
     
     
                //printing properties of the rectangles r1 and r2
                System.out.println("Properties of the First Rectangle \'r1\' " + "\n"+ "Color: " 
                        + r1.getColor() + "\n" + "Height: " + r1.getWidth() + "\n" +
                        "Width " + r1.getHeight() + "\n" + "Area: " + area1 + "\n");
              System.out.println("Properties of the Second Rectangle \'r2\' " + "\n"+ "Color: " 
                        + r2.getColor() + "\n" + "Height: " + r2.getWidth() + "\n" +
                        "Width " + r2.getHeight() + "\n" + "Area: " + area2 + "\n");
                }
     
                }

    Output
    Properties of the First Rectangle 'r1' 
    Color: yellow
    Height: 7.0
    Width 6.0
    Area: 42.0
     
    Properties of the Second Rectangle 'r2' 
    Color: yellow
    Height: 9.0
    Width 5.0
    Area: 45.0

    See "yellow" in both r1 and r2 where as I have assigned yellow to only r2. If I remove r2 only then I can see r1's color. Help please!


  2. #2
    Super Moderator Norm's Avatar
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    Default Re: Problem in Class, Displaying only one last change in value!

    You need to study what the static modifier does when used with a variable in a class.
    private static String color = "white";
    color is the only class member that has that modifier and is the only one that is not unique to each instance of the class.
    If you don't understand my answer, don't ignore it, ask a question.

  3. The Following User Says Thank You to Norm For This Useful Post:

    adnan.alvee (March 12th, 2013)

  4. #3
    Junior Member
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    Default Re: Problem in Class, Displaying only one last change in value!

    Thank you soo much norm! That solved it. So static sets it to only one value change or more like the recent change in any object in other classes, right?

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