I am a beginner in Java and my professor wants us to create a program that involves some math. The thing is that he wants the calculations in a separate method. Can someone please help me. The program will not run the result for some reason. I tried looking around this website and could not find the answer. Here is the code below:
import javax.swing.JOptionPane;
public class forFun {
public static void main(String[] args)
{
double x, y, z;
String xVal, yVal, zVal;
xVal = JOptionPane.showInputDialog("Enter first integer: ");
yVal = JOptionPane.showInputDialog("Enter second integer: ");
zVal = JOptionPane.showInputDialog("Enter third integer: ");
x = Double.parseDouble(xVal);
y = Double.parseDouble(yVal);
z = Double.parseDouble(zVal);
System.exit(0);
}
public static void sumOfStocks(double x, double y, double z)
{
double result = x * y * z;
System.out.println("The product of the integers is: " + result);
System.exit(0);
}
}
Here is the example of how the code should be
import javax.swing.JOptionPane;
public class forFun {
public static void main(String[] args)
{
double x, y, z;
String xVal, yVal, zVal;
xVal = JOptionPane.showInputDialog("Enter first integer: ");
yVal = JOptionPane.showInputDialog("Enter second integer: ");
zVal = JOptionPane.showInputDialog("Enter third integer: ");
x = Double.parseDouble(xVal);
y = Double.parseDouble(yVal);
z = Double.parseDouble(zVal);
double result = sumOfStocks(x, y, z);
System.out.println("The result is %d", result);
System.exit(0);
}
public static double sumOfStocks(double x, double y, double z)
{
double result = x * y * z;
return result;
}
}
Related
I have created this code, the GUI pops up and works perfectly, but the area is not being calculated correctly. Any Clue why? I am very new to Java coding, so any help is appreciated. Thanks in advance.
package pkg4.pkg2.pkgnew.project;
import javax.swing.JOptionPane;
public class NewProject {
public static void main(String[] args) {
String inputStr = JOptionPane.showInputDialog("Type 1 for the area of Triangle, 2 for area of Circle, 3 for Rectangle, and 0 for area of none of these.");
int i = Integer.parseInt(inputStr);
if (i == 1) {
String input = JOptionPane.showInputDialog("Enter the first value to calculate the area of a triangle: ");
int n1 = Integer.parseInt(inputStr);
String inp = JOptionPane.showInputDialog("Enter the second value to calculate the area of a triangle: ");
int n2 = Integer.parseInt(inputStr);
areaTriangle(n1, n2);
}
if (i == 2) {
String inpu = JOptionPane.showInputDialog("Enter a value to calculate the area of a circle: ");
double radius = Integer.parseInt(inputStr);
areaCircle(radius);
}
if (i == 3) {
String inp = JOptionPane.showInputDialog("Enter the first value to calculate the area of a rectangle: ");
int m1 = Integer.parseInt(inputStr);
String inp2 = JOptionPane.showInputDialog("Enter the second value to calculate the area of a rectangle: ");
int m2 = Integer.parseInt(inputStr);
areaRectangle(m1, m2);
} else {
return;
}
}
public static void areaTriangle(int n1, int n2) {
int areat = (n1 * n2) / 2;
JOptionPane.showMessageDialog(null, "The area of a triangle with your values is: " + areat);
}
public static void areaCircle(double radius) {
double areac = Math.PI * (radius * radius);
JOptionPane.showMessageDialog(null, "The area of a circle with your value is: " + areac);
}
public static void areaRectangle(int m1, int m2) {
int arear = (m1 * m2);
JOptionPane.showMessageDialog(null, "The area of a rectangle with your values is: " + arear);
}
public static void calcArea(int x) {
}
}
The problem with your code is that every time you parse the input into a string you are always using the same value of the string. Everytime you call your functions you are using all 1, 2, or 3 for your parameters into your area function calls. So you need to change the Integer.parseInt() to contain the new strings you get from the user like so:
String input = JOptionPane.showInputDialog("Enter the first value to calculate the area of a triangle: ");
int n1 = Integer.parseInt(input); //not inputStr <----------
String inp = JOptionPane.showInputDialog("Enter the second value to calculate the area of a triangle: ");
int n2 = Integer.parseInt(inp);//not inputStr <---------
areaTriangle(n1, n2);
I'm writing a program that takes the users input for height and weight then calculates the Body Mass Index from this. It uses separate methods for height, weight and BMI, these methods are called from main. The problem I'm having is I have absolutely no clue how to put the input from weight and height methods into the BMI method. This is what the code looks like:
public class BMIProj {
static Scanner input = new Scanner(System.in);
public static int heightInInches()
{
System.out.println("Input feet: ");
int x;
x = input.nextInt();
System.out.println("Input Inches: ");
int y;
y = input.nextInt();
int height = x * 12 + y;
return height;
}
public static int weightInPounds()
{
System.out.println("Input stone: ");
int x;
x = input.nextInt();
System.out.println("Input pounds ");
int y;
y = input.nextInt();
int weight = x * 14 + y;
return weight;
}
public static void outputBMI()
{
}
public static void main(String[] args) {
heightInInches();
weightInPounds();
outputBMI();
}
Thanks in advance.
I advise you to do a little bit more learning in java, specifically variables, declaring, initializing, etc.. Also learn class, constructors, etc..
You need fields for the class to save the inputed variables
I created a constructor to initialize the variables
You don't need to return anything in the methods if all you are doing is assigning values to your class fields and outputting info.
I did the curtsy of calculating the bmi for you
Anyway
public class BMIProj {
static Scanner input = new Scanner(System.in);
// Class vars
int height;
int weight;
double bmi;
//Constructor
public BMIPrj(){
//Initialize vars
height = 0;
weight = 0;
bmi = 0;
}
public static void heightInInches()
{
System.out.println("Input feet: ");
int x;
x = input.nextInt();
System.out.println("Input Inches: ");
int y;
y = input.nextInt();
int height = x * 12 + y;
return height;
}
public static void weightInPounds()
{
System.out.println("Input stone: ");
int x;
x = input.nextInt();
System.out.println("Input pounds ");
int y;
y = input.nextInt();
int weight = x * 14 + y;
return weight;
}
public static void outputBMI()
{
System.out.println("BMI: " + (( weight / height ) x 703));
}
public static void main(String[] args) {
heightInInches();
weightInPounds();
outputBMI();
}
You can assign the output of a method to a parameter like so:
int weight = weightInPounds();
When calling a method, you can pass in parameters:
outputBMI(weight);
The rest is up to you.
First the error was that the variables in the parameters of the object is not initialized. Then it started to give this error when initialized, Exception in thread "main" java.lang.NoSuchMethodError: Triangle.(DD)V
at testTriangle.main(testTriangle.java:6). Please help!
// main class
import java.util.Scanner;
public class testTriangle{
public static void main(String [] args){
double xcoord = 0,ycoord = 0;
Scanner scan = new Scanner(System.in);
Triangle object = new Triangle(xcoord,ycoord);
System.out.println("Welcome to the hypothenuse finder!");
System.out.println("Please input the first value(x): ");
xcoord = scan.nextDouble();
System.out.println("Please input the second value(y): ");
ycoord = scan.nextDouble();
object.radi();
object.toString();
}
}
import java.lang.Math.*;
public class Triangle{
double x;
double y;
public Triangle(double xcoord,double ycoord){
x = xcoord;
y = ycoord;
}
public double radi(){
return(Math.sqrt(Math.pow(x,2)+Math.pow(y,2)));
}
public void toString(){
System.out.printf("The x value is: " + x + " the y value is: " + y + " and the radius is : ", radi());
}
}
I have got your code to work, by putting the 2 classes into there own class files and I also changed this method toString() name, because there is already a built in method called toString(). So I changed it to string() and it seems to work.
TestTriangle Class:
import java.util.Scanner;
public class TestTriangle{
public static void main(String [] args){
double xcoord = 0,ycoord = 0;
Scanner scan = new Scanner(System.in);
Triangle object = new Triangle(xcoord,ycoord);
System.out.println("Welcome to the hypothenuse finder!");
System.out.println("Please input the first value(x): ");
xcoord = scan.nextDouble();
System.out.println("Please input the second value(y): ");
ycoord = scan.nextDouble();
object.radi();
object.string();
}
}
Triangle Class:
public class Triangle {
double x;
double y;
public Triangle(double xcoord,double ycoord){
x = xcoord;
y = ycoord;
}
public double radi(){
return(Math.sqrt(Math.pow(x,2)+Math.pow(y,2)));
}
public void string(){
System.out.printf("The x value is: " + x + " the y value is: " + y + " and the radius is : ", radi());
}
}
import java.util.Scanner;
public class Assignment3 {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
double pi = 3.142;
double T, v, a, x, r;
System.out.println("3.Centrifuge. The rotor of an ultracentrifuge rotates at x rev/s.");
System.out.println("A particle at the top of the test tube is r meter from the rotation axis.");
System.out.println("Calculate it’s centripetal acceleration.");
System.out.printf("Enter the number of rotation in rev/s : ");
x = input.nextInt();
System.out.printf("Enter the distance in meter : ");
r = input.nextInt();
T = 1/x;
v = (2*pi*r)/T;
a = (v*v)/r;
System.out.println("\n\nAnswer");
System.out.printf("The centripetal acceleration is : %.2f m/s^2\n", a);
}
}
Hi all. This is my coding and it cannot run when I put decimal point. how to fix it?
Replace input.nextInt(); with input.nextDouble();
x = input.nextInt(); // It will simply ignore decimal values
Hence you need to use nextDouble()
x = input.nextDouble(); // This will read the entire decimal value
You read a int with
input.nextInt();
Try
input.nextDouble();
Try it.
import java.util.Scanner;
public class JavaScannerDouble {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
String data = input.next();
double decimalValue = Double.parseDouble(data);
System.out.println("Decimal value : " + decimalValue);
// test of decimal value
double response = decimalValue / 0.1;
System.out.println("response : " + response);
}
}
I'm trying to build an app which computes the area of a triangle, as per my homework assignment. Not quite sure where I'm going wrong, but I input the lengths of the triangle and would like the proper area displayed according to Heron's formula: sqrt (s(s-a) (s-b) (s-c)). All I'm getting for output is -0.0. Here is the code:
import java.lang.Math;
public class Formula
{
double area; double s;
public double findArea(double sideA, double sideB, double sideC)
{
s = 1/2 * (sideA + sideB + sideC);
area = Math.sqrt(s*(s-sideA)*(s-sideB)*(s-sideC));
System.out.println("The area of the triangle is " + area);
return area;
}
}
And then I have another file for the main args
import java.util.Scanner;
public class findTriangleArea {
/**
* #param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
Formula triangle = new Formula();
double a,b,c;
// input triangle lengths a, b, c
Scanner inputTriangle = new Scanner(System.in);
System.out.println("Please enter triangle side a");
a = inputTriangle.nextDouble();
System.out.println("Please enter triangle side b");
b = inputTriangle.nextDouble();
System.out.println("Please enter triangle side c");
c = inputTriangle.nextDouble();
triangle.findArea(a, b, c);
}
}
1/2 is being computed in integer arithmetic, so like with all integer division, it's truncated -- in this case, to 0. Just write 0.5 and you'll be fine.
public class AreaOfTriangle {
public static void main(String[] args) {
Scanner scanner=new Scanner(System.in);
System.out.print("Enter the height: ");
double height=scanner.nextDouble();
System.out.print("Enter the base: ");
double base=scanner.nextDouble();
scanner.close();
double area=(base*height)/2;
System.out.println("---------------------------");
System.out.println("Area of Triangle is: "+area);
}
}
Heron's Formula:
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
double a, b, c;
a = sc.nextDouble();
b = sc.nextDouble();
c = sc.nextDouble();
double p = (a + b + c) / 2;
System.out.println(Math.sqrt(p * (p - a) * (p - b) * (p - c)));
}