No problem. I suppose this is what the discussion is meant for. Anyway, OP would benefit too.
On Mar 31, 11:05 pm, el mio uno y dos <[email protected]> wrote: > Hello agains, our companion wrotte "I wrote a code for a program that have 1 > superclass and 1 class extends" so i this do, and overriding a method. > > Thank you very much to discuss it with me. > > > > > Date: Mon, 30 Mar 2009 21:54:02 -0700 > > Subject: [java programming] Re: Logic error! > > From: [email protected] > > To: [email protected] > > > On Mar 31, 5:55 am, el mio uno y dos <[email protected]> wrote: > > > Hello bulimic,this is that i do, please i am a new on java, but i believe > > > that now is more clear the code. What do you think? > > > > public class Cilindro { > > > double pi = Math.PI; > > > double area; > > > double perimetro; > > > > public Cilindro() > > > { > > > > } > > > > public double area(double r, double h){ > > > > area = (2*pi*r*h) + (2*pi*r*r); > > > > return this.area; > > > } > > > > public double perimetro(double r, double h){ > > > perimetro = (4*pi*r)+(2*h); > > > > return this.perimetro; > > > > } > > > > } > > > > public class Circulo extends Cilindro{ > > Since circulo does not have any incentive to inherit from cilindro, > > circulo's class declaration can be written this way: > > public class Circulo{ > > } > > > Like you, I am learning too. Good luck. > > > > public Circulo(){ > > > > } > > > > public double area(double r){ > > > > area = pi*r*r; > > > return this.area; > > > } > > > > public double perimetro(double r){ > > > perimetro = 2*pi*r; > > > > return this.perimetro; > > > } > > > > } > > > > public class Main { > > > > /** > > > * @param args the command line arguments > > > */ > > > public static void main(String[] args) { > > > // TODO code application logic here > > > Circulo obj1 = new Circulo(); > > > Cilindro obj2=new Cilindro(); > > > double radio ,altura ; > > > Scanner input = new Scanner(System.in); > > > > System.out.println("Ingresa Radio: "); > > > radio = input.nextFloat(); > > > System.out.println("Ingresa Altura: "); > > > altura = input.nextFloat(); > > > > System.out.println("Area del circulo: " + obj1.area(radio)); > > > System.out.println("Perimetro del circulo: " + > > > obj1.perimetro(radio)); > > > System.out.println("Area del cilindro: " + > > > obj2.area(radio,altura)); > > > System.out.println("Perimetro del cilindro: " + > > > obj2.perimetro(radio,altura)); > > > } > > > > } > > > > Date: Mon, 30 Mar 2009 14:32:33 -0700 > > > > Subject: [java programming] Re: Logic error! > > > > From: [email protected] > > > > To: [email protected] > > > > > On Mar 31, 3:27 am, el mio uno y dos <[email protected]> wrote: > > > > > Hello bulimic, i think that circulo is not a inner class of cilindro. > > > > > I think that circulo is a subclass of cilindro. I send a copy of how > > > > > i do it. Please see it and tell me if is correct. > > > > Hello. I did not receive any copy. Anyway, we can discuss here. > > > > > Circulo inherits cilindro is odd. I think it would be more efficient > > > > if cilindro extends circulo as it can take advantage of code re-use. > > > > For example: > > > > public class Circulo{ > > > > public double area(double radius){ > > > > } > > > > public double perimetro(double radius){ > > > > } > > > > } > > > > > public class Cilindro extends Circulo{ > > > > public double area(double radius, double height){ > > > > // Use circulo's methods to calculate cilindro's area. Then > > > > return. > > > > double areaCirculo=area(radius), perimetroCirculo=perimetro > > > > (radius); > > > > } > > > > } > > > > > > > Date: Mon, 30 Mar 2009 11:53:33 -0700 > > > > > > Subject: [java programming] Re: Logic error! > > > > > > From: [email protected] > > > > > > To: [email protected] > > > > > > > On Mar 31, 1:36 am, jose luis garcia <[email protected]> wrote: > > > > > > > *Hello everybody... I have a problem. I wrote a code for a > > > > > > > program that have > > > > > > > 1 superclass and 1 class extends. the code it`s follow:* > > > > > > > > //Programa que realiza algunos calculos mediante las > > > > > > > caracteristicas de un > > > > > > > cilindro > > > > > > > > package cilindro; > > > > > > > > // @author louis > > > > > > > > import java.util.Scanner; > > > > > > > > public class Cilindro { > > > > > > > double pi = Math.PI; > > > > > > > > public Cilindro(){ > > > > > > > // super(); > > > > > > > > } > > > > > > > > public double areaCilindro(double r, double h){ > > > > > > > double area = (2*pi*r*h) + (2*pi*r*r); > > > > > > > > return area; > > > > > > > } > > > > > > > > public double perimetroCilindro(double r, double h){ > > > > > > > double perimetro = (4*pi*r)+(2*h); > > > > > > > > return perimetro; > > > > > > > > } > > > > > > > > public class Circulo extends Cilindro{ > > > > > > > > Circulo(){ > > > > > > > super(); > > > > > > > } > > > > > > > > public double areaCirculo(double r){ > > > > > > > > double area = pi*r*r; > > > > > > > return area; > > > > > > > } > > > > > > > > public double perimetroCirculo(double r){ > > > > > > > double perimetro = 2*pi*r; > > > > > > > > return r; > > > > > > > } > > > > > > > > } > > > > > > > > public static void main(String[] args) { > > > > > > > > // Cilindro obj = null; > > > > > > > Circulo obj1 = null; > > > > > > I suspect the culprit is the inner class. If I remember correctly, > > > > > > an > > > > > > inner class type declaration should be like: > > > > > > Cilindro.Circulo obj1 = null; > > > > > > > > double radio = 0,altura = 0; > > > > > > > Scanner input = new Scanner(System.in); > > > > > > > > System.out.println("Ingresa Radio: "); > > > > > > > radio = input.nextFloat(); > > > > > > > > /* System.out.println("Ingresa altura: "); > > > > > > > altura = input.nextFloat(); > > > > > > > */ > > > > > > > String resultado = "Area del circulo: " + > > > > > > > obj1.areaCirculo(radio); > > > > > > > > System.out.println(resultado); > > > > > > > > } > > > > > > > > } > > > > > > > > *Netbeans not generate any error. But at the moment that run the > > > > > > > program and > > > > > > > insert a float, Netbeans generate me this message:* > > > > > > > > run: > > > > > > > Ingresa Radio: > > > > > > > Exception in thread "main" java.lang.NullPointerException > > > > > > > at cilindro.Cilindro.main(Cilindro.java:66) > > > > > > > 2.23 > > > > > > > Java Result: 1 > > > > > > > GENERACIÓN CORRECTA (tiempo total: 3 segundos) > > > > > > > > * > > > > > > > I`m sure that is a logic error... help me please. Thanks! > > > > > > > * > > > > > > _________________________________________________________________ > > > > > Descubre todas las formas en que puedes estar en contacto con amigos > > > > > y familiares.http://www.microsoft.com/windows/windowslive/default.aspx > > > > _________________________________________________________________ > > > ¿Quieres ver los mejores videos de MSN? 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