Area And Perimeter Of Triangle - Decimal Formatting Error?
Sep 28, 2014
I am also having trouble with another program.
Java Code:
import javax.swing.JOptionPane;
import java.util.*;
import java.text.DecimalFormat;
import java.util.StringTokenizer;
public class ShelbyHarms_3_03 {
public static void main (String [] args) {
double a, b, c; //Input sides of triangle
double x; //Perimeter of triangle
double area; //Area of triangle
[Code] .....
Here are the errors:
ShelbyHarms_3_03.java:39: error: variable x might not have been initialized
JOptionPane.showMessageDialog(null, formatter.format(x));
^
ShelbyHarms_3_03.java:42: error: variable area might not have been initialized
JOptionPane.showMessageDialog(null, formatter.format(area));
^
2 errors
I'm doing a problem where the area of a triangle is returned (if valid). However, I want to return a message (i.e. 'triangle is not valid) if the triangle is invalid.
I'm not sure how to go about to doing this as my method (called area) will only let me return doubles. Possible to return a string in an else within my area method?
public class MyTriangle { public static void main(String[] args) { //triangle is valid if the sum of any two sides is bigger than the third System.out.println(isValid(3, 4, 5)); System.out.println(area(543, 4, 5));
I've been given a school assignment that reads, "Rewrite the main class Geometry so it takes in the dimensions for the triangle and ellipse as user inputs and create a Triangle and an Ellipse class. Use the appropriate variable types, constants, variable names and computational formulas.
Triangle class will have a computePerimeter and a computeArea methods Ellipse class will have a computeArea method Create Report class
• Create a method createReport that takes the values returned from Triangle and Ellipse and combines them in the following message and displays it. Format the values so that they have 2 decimals.
“The triangle has a perimeter of [perimeter] with an area of [area] while the ellipse has an area of [area]”
• Create a method switchReport that takes the original string from createReport and changes the message to display using the available methods in the String class
“The ellipse has an area of [area] while the triangle has an area of [area] with a perimeter of [perimeter]”"
I've run into a problem when creating the createReport method. Everytime i run it i get incorrect values for the perimeter and area (namely i get zero every time).
my code is as follows:
public class Triangle { public double base; public double height; public double hypotenuse; private double tArea; private double perimeter; public Triangle() { base = 0; height = 0; hypotenuse = 0;
[code]....
For the triangle class and
public class Report { Triangle tri2 = new Triangle(); Ellipse eli2 = new Ellipse(); public Report() { } public void createReport() { System.out.println("The triangle has a perimeter of "+tri2.computePerimeter() +" with an area of " +tri2.computeTArea() +" while the ellipse has an area of " +eli2.computeEArea() ); }
for the report class.the Geometry class allows you to input values and if i skip the report and simply print the perimeter and area they are correct. However with the report class it simply gives me zeros.
Create a program to input the length and width of a rectangle and calculate and print the perimeter and area of the rectangle. To do this you will need to write a Rectangle class and a separate runner class. Your program should include instance variables, constructors, an area method, a perimeter method, a toString method, accessor and mutator methods, and user input. Your runner class should include 3 Rectangle objects. One default rectangle, one coded rectangle, and one user input rectangle. All methods should be tested in the runner class.
This is my code:
import java.util.Scanner; public class Rectangle { double length; double width; public Rectangle() {
[Code] ...
What have I done??? I have created this program using the few different resources with which I am supplied, but I don't understand the resources.
I've been having trouble with this code for about a week and I've finally got it down to one error. Here is the code:
import java.util.Scanner; public class Triangle { public static void main (String[] args) { Scanner Console = new Scanner(System.in); System.out.print("Please enter the three lengths of your Triangle: "); double a = console.nextDouble();
[Code] ....
And here is the error:
Triangle.java:30: error: class, interface, or enum expected } // End class ^ 1 error
package areatest; import javax.swing.JOptionPane; public class AreaTest {
public static double areaTriangle (double length, double width){ //How to calculate the area of a triangle return .5f * length * width;
[Code] .....
When I try to get the area of a rectangle it gives me 9 no matter what input I give it. When I try to get the area of a triangle it gives me .5 no matter what input I give it. Same with the circle but it always gives me 12.56370...
I started with finding the area of a triangle, but now I'm trying to ask a user what kind of shape they want the area for, then ask questions to get the area. I can't figure out how to take the shape a person types to go to a certain case. It also says shape hasn't been initialized. I don't know how to do that.
import java.util.Scanner; public class TriangleArea { static Scanner sc = new Scanner(System.in); public static void main(String[] args){ char shape; String text = "Do you want to find the area of a triangle, square, rectangle, or trapezoid?"; System.out.print("Text"); switch(shape){
I've been scanning forums for answers to this problem, but most deal with simple programming that you might find in a classroom (i.e. "System.out.printf") which will not work in the GUI I'm attempting to complete. Here's the tale of the tape:
The GUI is a price calculator I'm developing for my company that takes input from drop-down menus and several Jtextfields and calculates the answer based on the values contained within each. It's completely done (and functional), so I'd rather not change too much if at all possible. Because I'm dealing with decimal values then I'm getting 9 decimal places in the output JLabel, though. In order to display the answer, I'm using a series of "totalPrice.setText(..." declarations.
Because there is a fair amount of text and the values in the calculation are constantly changing, is there a way to 'simply' format the output JLabel to display only 2 decimals? Or is there an alternative solution that would work--say with a JTextfield instead--without having to completely re-code the calculator?
Basically its a program where a user is prompted to enter the length of all three sides of a triangle and the program calculates the area by herons formula and can tell if the triangle is equilateral or Pythagorean. I am having trouble entering a formula to where all three enter sides cant possibly be a triangle. Here is my Program. Where the '?' is stated.
import java.util.Scanner; public class Triangle { public static void main(String[] args){ double a; double b; double c; double s; double x; double area;
I am writing a simple learning program that does basic math. Everything is working as needed except for when it comes to division. I need to know if there is a way to format the users input to two decimal places and that when the program checks the users answer against the division, it gives it a yay or nay. Right now, it wants the answer out to 12 decimal places.
My program is supposed to include The three sides of the triangle formatted to two decimal places The perimeter formatted to one decimal place The area formatted to one decimal place The unformatted area. It does run, but it is not decimal formatted. I have read my book to try and figure out how to do this, but it doesn't make since to me.
I'm attempting to format my doubles to two decimal places within my return statement. I have tried to use DecimalFormat but it gives me an error because my method needs to return a double and that results in a string being returned. I have also tried using the *100.00/100.00 method and that doesn't work when the number already ends in 0.
If I pass -150.00 it gives me -150.0 when I need two decimal places.
I'm having trouble formatting my output and issues with the decimal places. Here's my code:
import java.util.Scanner; import java.text.DecimalFormat; // Imports DecimalFormat class for one way to round public class lab3 { public static void main(String[] args) { String heading1 = "Hour", heading2 = "Distance Traveled"; int timeElapsed, hour, speed;
[Code] ....
And here's my output (Click on the image since it's pretty small):
javaIssues.png
Issue: 1) The Hours 2 and 3 aren't aligned to 1. 2) The 80 and 120 in Distance Traveled have 6 decimal places when it should not have decimals.
I have this error that keeps coming up any time I select one of my buttons. It actually doesn't hinder the performance of the project, everything works. But I am concerned I missed something and errors are never a good sign.On a slightly different note, I would like to figure out what the best way to format my output would be? I would like it to display as "100.00 F". I have a couple ideas on how to get the F symbol (or other symbol) by inserting something like
String degreesymbol = "F" or whichever it is and then returning that in the output string later. I can't get the decimal formatted correctly and I don't know how to print the degree symbol.Here is the code
So I want to format my output in a table much like the one in the book. I have an SECTable class and it displays the table one row at a time. 4 of the rows are in the 2D array in the SECTable class. The decimal position values are just displayed via a loop going from 12 to 1 (8 bits), 21 to 1 (16 bits), and 38 to 1 (32 bits) and the binary position values have their own class which contains an ArrayList of the binary position values as strings. Here's an example of how I want the table to be formatted (this is after an error has been generated so all the rows will be displayed):
And I need it to format similarly for 16 bits and 32 bits as well. Here's the display function for the list of binary position numbers:
public void displayList() { System.out.print("Binary Positions: "); for (int i = (posNums.size() - 1); i >= 0; i--) { System.out.print(posNums.get(i) + " "); } }
Here are the display functions for the rows (separated them so that there wasn't so much code in one function):
public void displayTable() { // Print the Binary Position Values displayBinPositions(); // Print decimal bit positions displayDecPositions();
[Code] ....
The print3rdRow and print4thRow are booleans to determine whether an error has been generated yet (user chooses from menu to create an error and the program picks a random bit to change and the erroneous data is put in the 3rd row and it's check bits are put in the 4th row). I tried doing spaces but it just wouldn't come out like I wanted.
package rockjava; import java.text.NumberFormat; import java.util.Scanner; public class file4 { public static void main(String[] args)
[Code] ....
Please Input Num of Pods + Num of Keys= 20.5 Exception in thread "main" java.util.InputMismatchException at java.util.Scanner.throwFor(Unknown Source) at java.util.Scanner.next(Unknown Source) at java.util.Scanner.nextFloat(Unknown Source) at alijava.file4.main(file4.java:14)
(It is not accepting double values. However working fine for integers.)
I'm using eclipse. I'm going to get straight to the point and give all the info I can, if the values in the first code box are used, shouldn't these values be left after all in the second box is done:
remainder=23, arr[0]=100, div=23/10=2.3, whole=2, and decimal=3?
When I use this code, div comes out to be just (2.0).
Java Code:
int leng=10; arr[0]=123; //int arr[1]=100; //int mh_sh_highlight_all('java'); Java Code: if (arr[0]!=arr[1]){ int remainder=arr[0]-arr[1]; arr[0]=arr[0]-remainder; double div=remainder/leng; //double div=Double.valueOf(remainder/leng); int whole=(int) Math.floor(div); int decimal=(int) ((div-whole)*leng); mh_sh_highlight_all('java');
I'm not sure were I'm going wrong in how div is being calculated, but I ultimately need div to be 2.3.
I've also used the second option commented out which still gives (2.0).
A triangle is defined by the x- and y- coordinates of its three corner points. Compute the following the following properties of a given triangle: the lengths of all sides, the angles at all corners, the perimeter and the area. The program must prompt a user for the point coordinates. I have created a class Triangle and a class TriangleSimulator, I am stuck and can't figure out why my program won't run correctly.
import java.util.Scanner; public class Triangle { Scanner in = new Scanner(System.in); private int x1; private int x2; private int x3;
class triangle { public static void main (String[] args) { System.out.println("Provide three side lengths - 000 to terminate."); int a = In.getInt(); int b = In.getInt(); int c = In.getInt();
[code]....
My problem is that when I enter 5,2,5 it should be isosceles and acute but it comes out as isosceles and obtuse, and when I type 5,5,5 it comes out equilateral and right. The only one that works is if I enter 3,5,4 it will come out as scalene and right. I been at this for a while and my math looks correct.
