## math456 3 years ago I need help, plz! Design and implement in Java, a class Rectangular tht supports two methods: 1). Area(double x, double y) tht returns the area of a rectangular of width x and length y. 2). perimeter(double x, double y) tht returns the perimeter length of a rectangle of width x & length y.

1. eSpeX

And what part did you get stuck on?

2. math456

public class Areas { public static void main( String [] args) { area (int, double x) like what should i write to return the area of a rectangular of the width & length?

3. eSpeX

Well, your area method takes an int and a double, so you probably want to return a double.

4. eSpeX

As for what you should put inside the method, consider the steps you must take to calculate the area. You will need to take in two variables, width and height, then multiply them together to get the area.

5. eSpeX

You have been given the definitions for both of your methods, just put the calculation inside that is needed to get the area and perimeter into each of their respective functions.

6. math456

oh so meaning: area ( width x, length y) area = w x h

7. eSpeX

Yes, but unless you are going to print it out within the method or assign it to a variable you can access, you will want to "return area = wxh;" or some similar operation.

8. math456

like this? public class Rectangular { public static void main(String [] args) { area (int length x; int width y); return area = x*y; } System.out.print( "area" ); }

9. math456

10. eSpeX

You're on the right track, try something like this: import java.util.*; public class Rectangle{ public static void main(String[] args){ double area, x, y; Scanner in = new Scanner(System.in); System.out.println("Please enter your width"); x = in.nextDouble(); System.out.println("Please enter your length"); y = in.nextDouble(); get_area(double x, double y){ area = x*y; System.out.println("The area of the rectangle is: " + area + "\n"); } } }

YOu should honestly look at the Java API for 2 reasons. 1 it uses doubles and it's a rectangle which is what you're looking for. http://docs.oracle.com/javase/6/docs/api/java/awt/Rectangle.html Rectangle getBounds() Gets the bounding Rectangle of this Rectangle. To make your own class like this you could do a few things. First is to set it up like you normally would. class rect { double w,h; rect() { //if you need constructor calls, most likely you would want this constructor below } rect(double length, double width) { this.w = width; this.h = height; //this will set the height and width of the new rectangle object you create //to create a new rectangle object you would do rect r = new rect(); or rect r = new rect(10,10); this makes both height and width 10. } next you will want methods TO SET and GET known as getters and settings... public setWidth(double w) { this.w = w; } public getWidth() { return w; //returning will return the global variable at the top which is our width. } same will be done with height.

12. eSpeX

Given the examples provided earlier, you may be offering a solution above his experience.

Next you could make a class that extends the rectangle class i.e., class rect extends Rectangle2D.Double { //code } this overrides Rectangle and you can use it's methods, or make your own.

public void setWidth(double w) { this.w = w; } public double getWidth() { return w; //returning will return the global variable at the top which is our width. } IS what should be stated above.

I don't think it's too hard, this is basic stuff. I explained in my comments what does what. I would assume that if he were too new, he wouldn't understand what the Scanner is either :P.

16. eSpeX

Fair enough, I did consider that as I typed it. :)

Imo it's better to see correct and complete code than to fumble around a lot.... OF course learning it yourself makes you understand it better, a good combo of both if perfect imo.

18. math456

@hartnn @.Sam. ??

19. math456

@eSpeX i don't hv to use Scanner problem in this program!

20. math456

@ganeshie8 ?

.....?

22. math456

i tried this, but it shows me error!! public class Rectangular { public static area(double x, double y) { return x*y; } public static perimeter (double x, double y) { return (2*x + 2*y); } }

23. math456

yes because you are not doing anything.

Basically when you create an object it's like making the frame.

in the oracle trail it talks about a bicycle.

it has methods like speed up, speed down, brake, etc. This is what we are doing. If you look above at what I said you can make it work.

In your own class right now you want to make a main method and that main method will create what you need.

class rect { double w,h; rect() { //if you need constructor calls, most likely you would want this constructor below } rect(double length, double width) { this.w = width; this.h = height; Constructor calls are important.

30. math456

public class Rectangular { public static void main (String [] args) { double width,length; x= width; y= length; rectangular (); return x*y; public static perimeter (double x, double y) { return rectangular (2*x + 2*y); } } } Still shows error!

31. math456

can't u tell like what are my mistakes and wht do I need to write instead?

32. math456

33. math456

so this is the new one and it compiles well but I only need the print statement to return the area of a rectangular of width x and length y.! @eSpeX @KonradZuse public class Rectangular { public static void main (String [] args) { } public double area (double x, double y) { return (x*y); } public double perimeter (double x, double y) { return (2*x + 2*y); } }

34. eSpeX

@math456 You do not have anything calling those methods, therefore you have nothing to catch the returned values. If you are going to make it without interaction from a user, why not just use System.out.println instead of a return statement?