Calculating Area Of A Rectangle (height Multiply By Width)
Mar 19, 2014
I was suppose to create a simple Java program for calculating the area of a rectangle (height * width). Then check the user’s input, and make sure that they enter in a positive integer, and letting them try again if they enter in a negative number. (I'm not sure how to get them to try again.
I am suppose to use an "if" statements and indeterminate loops to achieve the solution. The program will have the following requirements:
1. Ask the user to enter in both a height and width (as an integer)
2. If the user enters in a negative number, display an error
3. If the user enters in a negative number, give them another chance to enter in the correct value
4. Calculate the area and display to the screen once two positive integers have been entered.
import java.util.Scanner;
public class RectangleAreaCalc
{
public static void main(String[] args)
{
int length;
int width;
int area;
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.
Any way to get my Java window to open with a certain width and height. I've been googling and haven't found to much valuable information. Here is what I have so far.
import javax.swing.*; import javax.swing.event.*; import java.awt.*; import java.awt.event.*; public class JavaWindow{ //Bring up the frame. private JFrame f = new JFrame("JavaWindow");
[Code] ....
When you compile that it runs a small window. I would like that window to be bigger when the file opens.
I have a requirement where in the content of the text area is dynamically populated from the database. I am able to successfully retrieve and display the data on the text area.
However when the content is too large, I am not able to dynamically set the height of the text area. When I try to display the same as a label, the display is flawless, dynamically sets the height as per the content. So, I tried to create a label, with same content and dynamically bind the height to the preferred height as below, but it doesn't work.
// Generate User Note Description TextArea textArea = new TextArea(); Label text = new Label();
// SETTING THE TEXT TO A LABEL TO RETRIEVE THE HEIGHT text.setText(usrNotes.getNote().trim());
I am supposed to be doing a class assignment that calculates the area of a triangle and outputs with JOptionPane. I was able to fix some errors, but it's uncovering more errors.Here is my code:
public class Area { public static void main (String [] args) { double a, b, c; //Input sides of triangle double x; //Perimeter of triangle double area; //Area of triangle StringTokenizer st;
//program that calculates the circumference and area of a circle
import java.util.Scanner; public class circle{ public static void main(String[] args){ Scanner input= new Scanner( System.in); double r; //declares radius
[Code] .....
And here is what is displayed in the command prompt when I compile my code:
circle.java:17: error: cannot find symbol r.input.nextdouble();//entered the radius symbol: method nextdouble() location: variable input of type Scanner 1 error
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.
Here is the program I wrote for calculating the circumference of a circle.
//circumference.java //program that calculates the area and circumference of a circle import java.util.Scanner; //program uses class scanner public class circumference{ //main method begins execution of Java application public static void main(String args[]){
[Code] .....
Even though my code compiles and runs without any errors, the program doesn't calculate the circumference.
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 am trying to create a program that will estimate a child height based on the height of the parents. It should ask the user to enter a String representing the gender, so m or M for a male and f or F for a female. The program must handle both upper or lower case gender entries. I need it to ask the user for the height of both parents in two parts:
1. for Feet and store in an int variable. 2. for inches and store and int variable.
So for example if the father is 6' 2'', the user would enter 6 when asked for feet and 2 when asked for inches. Convert the height of the each parent to inches. hint 12" in one foot.
Apply the following formulas based on gender (must use an if statement(s)):
Develop a method that accepts as data input three integer numbers, calculates the sum and the product of the numbers, and displays the sum and product.
I would like to multiply the amount stated inside program by user input. I currently have
public static void setTicket(double ticket) { //if statement for tickets if (ticket == 1) Ticket = 10.00; else if (ticket == 2) Ticket = 20.00; else if ( ticket == 3) Ticket = 30.00;
The user should enter 2 and the value should show 20.00. This does work however im looking for a way to say enter 2 = 2*10 instead of stating each value individually.
My assignment is to write some code that will multiply every number in an array by 2 and print it out. This is using a site zyante which is a interactive online book kind of thing.
I have tried For (i=0; I < 8; i++) with like userVals = userVals * 2) }
And it doesn't like that so i'm guessing i am no where close to right. The chapter doesn't give me any example of doing anything close to this so i am completely lost on what i have to do.
This is the program :
import java.util.Scanner; public class NegativeToZero { public static void main(String[] args) { Scanner scnr = new Scanner(System.in); final int NUM_ELEMENTS = 8; // Number of elements
public static void main (String [] args) { int a = (int) 0.25; int b = (int) 1.25; int result = a + b; System.out.println("Result of addition is "+ result); } }
I am trying to make a program to multiplies two numbers without using the "*" operator. My idea was to add x number y amount of times, which is the same as multiplication. I did this with a for loop, but zero is always returned as the answer. How can I fix this?
public class secondMult { public static void main(String[] args){ System.out.println(multWithSum(4,5)); } public static int multWithSum(int x, int y){ int sum = 0; for(int i = 0; i==y;i++){ sum = sum + x; } return sum; } }
import java.awt.Graphics2D; import java.awt.Rectangle; import java.awt.event.KeyEvent; public class Racquet { private static final int WIDTH = 60; private static final int HEIGHT = 20;
[code]....
The problem arises at the portion of the code that says
private int Y = game.getHeight() - 70;
I am not actually getting any compiler errors, but when I try to run the program, the command prompt pops up with this message:
Exception in thread "main" java.lang.NullPointerException at Racquet.<init>(Racquet.java:19) at Game.<init>(Game.java:10) at Game.main(game.java:58)
What I want to do is make it so a GUI object that I created moves with the screen when I change the height. If I change it to private int Y = 330; the program works just fine.
So I'm trying to make a bar graph, each bar will increment the height by about 10 pixels. To do this, I'm making an array of bars. For some reason, using fillrect I cannot not increase the size more than 10 by 10, if I do, it will only show the 10 by 10. I want the bars to increase in height by 10 each time.
import java.awt.*; import java.awt.event.*; import javax.swing.*; import javax.swing.event.ChangeEvent; import javax.swing.event.ChangeListener; public class AssortedAssortmentsOfSorts extends JFrame
