I am trying to make a calculator using Java GUI. I've managed to make an ActionListener and add it to a button, but I've made an error in my code that I'm unsure of how to solve. Because of how I've written the code, only one number can be placed in the text field. For example, the an ActionListener for the three button on the calculator was added to the button, but no matter how many times the user presses the button, only one 3 will appear in the text field. The code is below:
import javax.swing.*;//import the packages needed for gui import java.awt.*; import java.awt.event.*; public class Calculator { public static void main(String[] args) { JFrame window = new JFrame("Window");//makes a JFrame window.setSize(300,350);
[code].....
As you can see, because the compiler forces the String variable to be final, so when the user presses the button, the code simply shows how a space character and three character would look like, because the String variable can't change. How do I write my code so that every time the user presses the button, a character is added to the text field?
i have a similar problem but what i need to do is to detect an exused absent of which in my notepad is represented by 00 and 0 being an unexcused absent, anyway if a student has an excused absent example a quiz for that day will be deducted from the total quizzes example if i was the teacher and had 2 quizzes of 10 items each and she was absent in one of the quizes instead of let say her score was 9 on the first quiz it should go 9/10 and if it was an unexcused absent 9+0/20 anyway this is my java code and notepad example
import java.io.*; import java.util.*; import java.lang.*; public class GradingSystem { public static void main (String[] args) throws FileNotFoundException
I am trying to make GPA calculator. I decided to use only switch statement and make it as simple as possible. The point is to enter as many classes and students as user wants. I keep getting credit points 0 at the end and also text format is not good too. Here is the code.
import java.util.Scanner; import java.io.*; public class SwitchExercise{ public static void main(String[] args) { String grade = ""; String grades=""; String coursename=""; String headingleft="COURSES";
I am having problems with my code I have added the multiplication and division but they will not display also how can I correct any error when dividing by zero?
import java.awt.*; import java.awt.event.*; public class calculator2 extends java.applet.Applet implements ActionListener { TextField txtTotal = new TextField(""); Button button[] = new Button[10];
So I was making a Java Calculator that only adds. The problem is that the numbers are not adding. I think it is because whatever has been clicked is not being saved to be added.
I am a beginner with Java. I have never used SWING before but I have to use it now and I am clueless. I don't know if what I am doing is right.I need to create a simple calculator. My problem is getting the buttons the user clicks to appear in a text field. I know I haven't added the =/*- buttons yet.
I have left actionPerformed practically blank, what to put in ?
import javax.swing.*; import java.awt.*; import java.awt.event.*; /** * Created by IntelliJ IDEA. * Date: 11/12/2014 * Changing Face Program. */ public class Calc extends JFrame implements ActionListener
My assignment is to design a simple GUI calculator using the stack data structure to perform additions, subtractions, multiplications and divisions. But i having error while i press the action there.
import java.awt.*; import java.awt.event.*; import javax.swing.*; import java.util.*; import java.util.Stack; public class JCalculator implements ActionListener {
I need to do a simple while loop pay calculator. I am very new and not sure what I need to do to put all the requirements in the new code from another code. Here is my code that doesn't work yet.
1.Place the wage calculation routines in a while loop. 2.Allow the user to input an individual's hours worked. 3.Accumulate the total regular hours worked, the overtime hours worked, the amount of the regular pay, the amount of overtime pay, and the total payroll, for all of the employees entered. 4.Allow the user to enter a zero (0) as the Boolean expression to end the loop. 5.When the loop ends print out all of the accumulated totals with appropriate labels, each on a separate line.
import java.util.Scanner; public class WhileLoopPayCalc { public static void main(String [] args) { final double REGULAR_HOURS = 40f; final double HOURLY_WAGE = 12.5f; final double OVERTIME = 1.5f; double wage = 0f;
package name;swing library found in javax called to use the graphical contents.
import javax.swing.*; //creating the contents for the calculator public class calc { JButton btn1= new JButton("1 "); JButton btn2= new JButton("2"); JButton btn3= new JButton("3");
[code]....
I have tried different sizes for the 'TextField' but when I change the size, the position changes instead of the size itself.
How can I make the numbers to stay at the textfield of my calculator instead of disappear like when I type 1 then hit the + sign the number 1 disappears from the textfield I would like to have this (1+1) showing in the text field and also if try to press only + , * , - , / to show error.
Our goal is to write a pretty simple program, one that takes the 12 digit UPC code entered by a user and to not only spit it back out in a format with dashes using toString, and also returns the first digit, a 2 more groups of digits numbering 2-6 and 7-11, and finally display the 12th digit. It then performs an equation to check the last digit and make sure the UPC code is correct.
However, being so new to java (I only learned visual basic before), with this I was introduced to two new concepts that for some reason I simply cannot grasp for the life of me: Using and calling the toString method, and calling on methods that are created in a completely different class file.
The first section of code is my UPC class, which is meant to contain all my methods as well as the toString to be called on:
public class UPC { // Instance variables private int itemType; // digit 1 private int manufacturer; // digits 2,3,4,5,6 private int product; // digits 7,8,9,10,11 private int checkDigit; // digit 12
How can i write a java program that simulate a simple calculator that performs the basic arithmetic operations of JAVA. (JOption Pane and Repeat control structure)
Example : Addition, Subtraction, Multiplication, Division.
The program will prompt to input two floating point numbers and a character that represents the operations presented above. In the event that the operator input is valid, prompt the user to input the operator again.
So, I'm working on a Tip Calculator for fun. I have everything worked out for the most part. The feature I am trying to add is to give the user the amount of change they'll get back from their transaction. I do not ask the user any information other than what is their bill.
Please enter your bill total : 5.50 Please enter your name : some name Total : 5.50 Tax : 0.48 -- Based off a tax rate of 8.75% Total with Tax : 5.98 -- 20 percent Tip : 1.10 Total with Tax and 20 percent Tip : 7.08 Total change : <-- I believe this will be about $2.92
I want the total bill to round to the nearest $10 value (e.g. for $5.50, calculate bill to $10. For $13.00, calculate bill to the $20.00, and so on... This way I get an accurate amount of change to give back to the user.
I made a MVC calculator. I was wondering if you could take a look at my design and if I was on track. I am still working on getting it to actually calculate something. All the buttons respond and print text on the JTextField but it is not calculating.
package calculator.MVC; import javax.swing.JButton; import javax.swing.JTextField; public class CalculatorModel { private int sum; private int number; private char opt;
I am making a calculator in Java. However, when I press the "=" button on my calculator, it always returns 0.0, no matter what. I don't understand why? The code is below:
import javax.swing.*;//import the packages needed for gui import java.awt.*; import java.awt.event.*; import java.util.Arrays; import java.util.List; import static java.lang.Math.*; public class CalculatorCopy {
import javax.swing.*; public class BasicCalculator{ public static void main (String[] args) { String output=""; double n1,n2; String operation; operation= JOptionPane.showInputDialog("Please enter your operation");
I have the basic workings of this program just doing all the printing at the end is throwing me off. Anyway here are some of the requirements and my code:
1. Allow the user to input an individual's hours worked. 2. Accumulate the total regular hours worked, the overtime hours worked, the amount of the regular pay, the amount of overtime pay, and the total payroll, for all of the employees entered. 3. Allow the user to enter a zero (0) as the Boolean expression to end the loop. 4. When the loop ends print out all of the accumulated totals with appropriate labels, each on a separate line.
import java.util.Scanner; public class WhileLoopPayCalc { public static void main(String [] args) { final double REGULAR_HOURS = 40f; final double HOURLY_WAGE = 12.5f; final double OVERTIME = 1.5f;
I am facing problem during calculation in my awt calculator. It is showing NumberFormatException. Below is part of code.
if(e.getSource()==b14)//On button 14, label is "/" { String v1=tf.getText().toString(); num1=num1+Integer.parseInt(v1);//num1 is as integer variable tf.setText("");//tf means textField }else
I'm new to java and have been coding for a few hours. I tried to create a calculator (Which has no GUI, just text inputs)which will let you select how to process the two integer (Add, minus, times etc.) I cant seem to get it to work. I will put in the process way such as times and have entered two integers and every time it doesn't work. Here is my code:
import java.util.*; public class Calculator { public static void main (String args[]) { int input1 = 0; int input2 = 0; int answer = 0;
I am currently working on a small java programm. I use netbeans for it. And obviously I am new to java.
Basically its a calculator that change the input value into another value: like 10 € into whatever $ and same with Inch and Centimeters.
Therefore I need a second jDialog Form where i can change the factors for the calculator and start the calculator again.
Here is my problem: I can open the second Dialog but if I want to change the factor it doesn't change the value in the variable and the second calculator frame is with the old factors. It seems the double variable isn't working globally
So I am working on a PostFix calculator that is used in command line for a class project, and I am having a little trouble on developing a memory for it. I have been told to create a hashMap and I have researched it and understand the basics of it. I have the calculating method working, but what I am having trouble trying to implement a way for the user to declare variables. For example this what the user should be able to do:
> a = 3 5 + 1 - 7 > bee = a 3 * 21 > a bee + 28
[code]....
I just need to be able to save the answers as a variable the User names, such as the example and let the user be able to use the variables later.
the program basically has a random number generating, and I want to ask the user to try to guess the number, and keep guessing until the number is right. In addition to this, I need to put in extra conditions for too high or too low by 10. So for example, if they user guesses a number and its off by more than 10, then it prints that they guessed too high, and if its below 10 they guessed too low.
import java.util.*; public class RandomNum { public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
[code].....
Modify the program to keep the user trying to guess the number till he/she gets it right, and stop once you guess the right number.Too high, high, too low, too low( If it's off by more than 10 = way too high, if its less than 10, way too low)