JSP Calculator - Performing Basic Operations On Numbers
Jul 8, 2014I want a simple jsp page that performs basic operations on numbers such as addition, subtraction, multiplication, division and modulus . How to run that file?
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Simulate Simple Calculator That Performs Basic Arithmetic Operations Of JAVA
Sep 9, 2014How 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.
Sample Output :
First number 7
Second number 4
Menu
<+> Addition
<-> Subtraction
<*> Multiplication
</> Division
Enter Choice: * <enter>
The answer is 28.
LISP Expression - Performing Operations
Jan 29, 2015Given a LISP expression, perform operations on the expression. There will be no list elements that also contain a list such as '(A (B (C D))), which has one atom and one list but the list contains a sublist
INPUT: There will be 5 lines of input. Each line will contain a valid LISP expression. There will be a space between each atom and each list. There are no spaces immediately after or immediately before parentheses in a list. The entire expression must be inputted as a single string.
OUPUT: Perform the given operation on the like numbered expression. The 5 operations are:
1. Print the expression with the list in reverse order. The list will contain only atoms.
2. Print the expression with the list written with consecutive duplicates encoded as sublists in (count element) order. The list will contain only atoms.
3 Print the expression with the list written with consecutive duplicates encoded as sublists in (count element) order except that singletons are listed as atoms. The list will contain only atoms.
4. Print the expression with the list written with every Nth element deleted and where N is the last element of the list.
5. Print the expression written as 2 expressions where the number of lists in first expression is the last element of the expression.
SAMPLE INPUT SAMPLE OUTPUT
1. '(A B C D) 1. ′(D C B A)
2. '(A A A A B C C A A D E E E E) 2. ′((4 A) (1 B) (2 C) (2 A) (1 D) (4 E))
3. '(A A A A B C C A A D E E E E) 3. ′((4 A) B (2 C) (2 A) D (4 E))
4. '((4 A) (1 B) (2 C) (2 A) (1 D) (4 E) 2) 4. ′((4 A) (2 C) (1 D) 2)
5. '((4 A) (1 B) (2 C) (2 A) (1 D) (4 E) 3) 5. ′((4 A) (1 B) (2 C)) ′((2 A) (1 D) (4 E) 3)
Basic Calculator Functions
Jul 2, 2014my task is to add a few functions to an example calculator. I managed to add a divide button but I simply can't figure out how to add a working Pi and reciprocal function.
package newjavaproject;
import java.awt.*;
import java.awt.event.*;
import java.applet.*;
public class CalculateurNC extends Applet {
[code]....
Basic Cost Calculator
Oct 20, 2014Why I am getting errors for this program I (tried) to write. I am new to java.
import java.util.Scanner;
public class TheBarkingLot {
public static void main(String args[]) {
int n;
Scanner input = new Scanner(System.in);
System.out.println("How many large dogs are boarding today?");
[Code] ....
Basic Grade Calculator
Jan 24, 2015im considered quite the "javanoob" as my account name states..The assignment is to basically take a number that is entered by a user, and based off what they type in, display a corresponding grade letter. For example, if they enter a number between 90-100, they should receive a response that they received an "A". Now, this is fairly simple using an if/else statement, but my professor wanted us to implement this, using a switch case to teach us the difference.
import java.util.*;
public class SwitchTest
{
public static void main(String[] args)
{
Scanner scan = new Scanner(System.in);
System.out.println("Please enter a number to find out what letter grade you have recieved");
[code]...
Basic GUI Calculator - Display Amount Of Commission And Total Annual Salary In Dollar Format
Apr 28, 2014So, I am supposed to write a program that calculates the total annual compensation for a salesman using user input for the salary, sales, and commission rate (list of 3 predefined commission rates. have to display in dollar format the amount of commission and total annual salary.
CommCalc class
public class CommCalc
{
//attributes of class, stored data
private double sales;
private double salary;
private double rate;
//and a total field? beware stale data.
//store sales argument from sales field
public void setSales(double sal)
[Code] ....
I know that i have to fix some of the semantics . I have this code that I made earlier, is there an easy way to make it into a GUI interface? Or will I have to go throughthe code lines to add the JOptionPane? And I am a little confused on how to make a list (array) for the commission rate.
Java Calculator - Numbers Are Not Adding
Jul 12, 2014So 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.
import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
[Code] .....
Extending Calculator - Added Function To Square Numbers
Feb 14, 2014I am new to java and during my classes we built a basic calculator. I want to extend my calculator and added function to square numbers.Here is my program:
Java Code:
package calculator02;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
[code]...
Postfix Calculator Doesn't Compute Negative Numbers
Nov 16, 2014My verify method also always returns false. So I'm given three classes to begin with. Calculator, Expression, and InfixExpression and they are listed below.
The goal is to create a class called PostfixExpression that extends Expression and can read and calculate postfix expressions.
My evaluate() method works for most calculations but when it needs to return a negative value it just returns the positive equivalent.
Also, my verify method always returns false and I can't pinpoint why.
Here's my current code. Some things are commented out for debugging purposes.
import java.util.Scanner;
/**
* Simple calculator that reads infix expressions and evaluates them.
*/
public class Calculator
{
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
[Code] .....
Java Calculator - Making Numbers To Stay At Textfield
Jul 12, 2014How 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.
this is my code
public class Calculator extends javax.swing.JFrame {
private double TEMP;
private double SolveTEMP;
Boolean addBool = false;
Boolean subBool = false;
Boolean divBool = false;
Boolean mulBool = false;
String display = "";
[Code] ....
Performing Regular Expression - Valid Last Name
Feb 4, 2015I have some problems about performing regular expression. In the following code, the output as a result is being "valid last name". But in my opinion, it should be "invalid last name". Because "Doe" has not any space, apostroph or any hypen. Look at the regular expression statement: "[a-zA-Z]+([ '-][a-zA-Z]+)*"
package deneme;
public class Deneme {
public static void main(String[] args) {
String lastName = "Mc-Something"; // Mc-Something
if(!lastName.matches("[a-zA-Z]+([ '-][a-zA-Z]+)*"))
System.out.println("Invalid last name");
else
System.out.println("Valid last name");
}
}
I know that the asterisk qualifier means character(s) in any number.(Is this wrong?) So for "Mc-Something", 'M' corresponds to [a-zA-Z], 'c' corresponds to +, - corresponds to [ '-], 'S' corresponds to [a-zA-Z], "o" corresponds to +, and finally "mething" corresponds to *, doesn't they? But for "Doe", there is no any space, apostroph or hypen.
String To A Double In Scanner - Performing Calculation?
Apr 23, 2015This may be a multipart question. Basically I have to write a program that accepts a string, converts it to a double splits it and then performs a calculation.
public static void main(String[] args) {
String input = ""; // initalize the string
boolean isOn = true; // used for the while loop...when false, the program will exit.
String exitCommand = "Exit"; // exit command
String[] token = input.split(("(?<=[-+*/])|(?=[-+*/])"));
[Code] ....
This is the error I get:
Enter a math problemException in thread "main" java.lang.NumberFormatException: empty String
at sun.misc.FloatingDecimal.readJavaFormatString(Floa tingDecimal.java:1842)
at sun.misc.FloatingDecimal.parseDouble(FloatingDecim al.java:110)
at java.lang.Double.parseDouble(Double.java:538)
at Calculator.main(Calculator.java:22)
[Code] .....
How do I go about actually fixing it. Without that line commented out I get this:
Enter a math problem
2+2 <-What I entered
[Ljava.lang.String;@135fbaa4
Also, how would I go about using the submethods to check for valid operands and operators (also part of the problem) I have the actual lists made obviously, but am unsure how to get those to work with the problem.
Reading Dat File And Performing Withdrawals And Deposits
May 3, 2014So I have these two programs
importjava.util.Scanner;
public class ManageAccounts
{
[Code].....
and i need to create a .dat file and have it perform the tasks it states, what to do, I've just been looking for existing codes and trying to modify them because i have a very limited knowledge of programming.
Int And Double - Performing Floating Point Arithmetic
Sep 19, 2014I am new Java Programming and I am struggling to pass my Java class. How to perform Java but I am trying. For this particular assignment I supposed to:
* Change all variables' data types to double.
* Change the two prompts to request double values
* Change change the two calls to the nextInt() method to nextDouble().
This is the original assignment:
import java.util.Scanner;
public class ArithmeticDemo
{
public static void main(String[] args)
{
Scanner input= new Scanner(System.in);
int firstNumber;
int secondNumber;
int sum;
int difference;
int average;
[code]....
2D Array Computation - Performing Certain Matrix Calculations
Apr 22, 2015I've created several methods in another class to perform certain matrix calculations. Do I need to have mutator method in this calculation class to define the column length of the matrix object? I understand why the following code is not working, but I was hoping to get a quick and easy workaround. I'm not sure how to initialize the size of the column for newMatrix within the method.
public int [][] sum(int matrixOne[][], int matrixTwo[][]) {
int sumMatrix [][] = new int[matrixOne.length]["WHAT TO PUT HERE"];
for (int i = 0; i < matrixOne.length; i++) {
for (int j = 0; j < matrixOne[i].length; j++) {
sumMatrix[i][j] = matrixOne[i][j] + matrixTwo[i][j];
System.out.println("matrixSum" + sumMatrix[i][j]);
}
}
return sumMatrix;
}
Then I will use this method to print the new matrix:
public void printMatrix(int newMatrix [][]) {
for (int i = 0; i < newMatrix.length; i++) {
for (int j = 0; j < newMatrix[i].length; j++) {
System.out.print(newMatrix[i][j] + " ");
}
System.out.println("");
}
}
Is all of this overkill and should I just define all the methods within the same class to avoid these issues?
Performing Method On Instance Inside Abstract Class
Mar 12, 2015How do I create an instance of a class in a method?
I am a bit rusty whenever I think of instances. I always think of main method and objects when I see instance which gets me confused on what to do when I am not in a main method. The example:
I have a abstract class, School, and inside School I have some methods that must preform some action on an instance. For example, there is a move() method that must move the instance of School. Another method named, personOld(), which returns whether or not an instance of School surpassed some determined age.
How do I do this and create this instance?
JavaFX 2.0 :: TreeView - Performing Drag / Drop With No Selection
Jul 14, 2014How do I keep an item (TreeItem) from being selected when performing a drag -n- drop? I don't want it to be selected because it will end up making the target disappear (selection of TreeItem changes target panel).
Related question: Is there a way to "veto" a tree selection change as well?
Swing/AWT/SWT :: Disable Event While Performing Long Running Task
Apr 28, 2015I have in my application a button that when it is pressed, runs a long running task (usually takes a couple of seconds....).
My problem is that while the task runs, I want to stop the button from receiving clicks. Unfortunately this is something I have not achieved.
I have tried creating a new thread and calling the long running method, and using the Display.geCurrent().asyncExec...
Examples of what I have tried so far:
myButton.addSelectionListener(new SelectionAdapter() {
@Override
public void widgetSelected(SelectionEvent e) {
if (myList.size() > 0) {
myButton.setEnabled(false);
myButton.setGrayed(true);
[Code] .....
In both cases, while the button is disabled and the cursor busy, if the user clicks the button, the long running method is ran several times - and this is what I want to avoid.
How To Count Primitive Operations
May 2, 2014I have having some trouble on counting the primitive operations on the pseudocode given below:
Algorithm 4. MaximumArray(Arr)
Input: A 1-D numerical array Arr of size n
1) Let CurrentMax = a0
2) For i = 1 to n-1
3)If ai > CurrentMax Then CurrentMax = ai
4) End For
Output: CurrentMax, the largest value in Arr
As of now, I know that for Line 1 there are 2 operations (one set and one read). I don't know how to figure out the for loop and If statement (line 2 and line 3 too).
Nested Loops Or Set Operations?
Oct 10, 2013Is there any advantage to using Java's operations defined in sets or collections over inspecting in nested for-loops?
For example, suppose I want to keep items from one array that do not appear in another, I could do:
for( PrimitiveType prim_1 : someArray ){
for( PrimitiveType prim_2 : otherArray ){
if( prim_1 != prim_2){
///put in some return list
}
}
}
Or else I could do:
ArrayList<NotPrimitive> excludedElements =
new ArrayList(Arrays.asList(primitiveArrayToExclude));
for( PrimitiveType elem : someArray){
if( ! excludedElements.contains( elem ) {
//put in some return list
}
}
I personally see no improvement in legibility nor any reduction of error potential.....
I/O / Streams :: Any Way To Parallel I/O Operations
Jul 31, 2014I've been wondering about this for a while. Is there any way to parallel I/O operations or is this a bad idea? If you could create two lists of good and bad ways to parallelize I/O.
View Replies View RelatedUsing A Menu For Stack Operations
Dec 3, 2014I am working on implementing a stack using a linked list. Programming the stack operations (push, pop, isEmpty, etc.) was easy but my directions were to provide the user with a menu to choose the operation that he/she wishes to perform. I am new to JFrames/Menus so how to make the stack operations available in a menu.
View Replies View RelatedIllegal Start Of Operations For All Methods
Apr 21, 2015Where are all these illegal start of operations and all of these other method errors coming from.I've written enough methods not to have this problem.
----jGRASP exec: javac -g Assessement.java
Assessement.java:29: error: illegal start of expression
public void addQuestionAnswer(){
^
Assessement.java:29: error: illegal start of expression
[code].....
How To Compute All Possible Arithmetic Operations Of 4 Integers
Nov 25, 2014I'm new to Java and I want to write a program that compute all the possible arithmetic operations of 4 integers.
For example, if the user enter 1, 2, 3, and 4 respectively, then I want the computer to print out the following results:
1 + 2 + 3 + 4
1 + 2 + 3 - 4
1 + 2 + 3 * 4
1 + 2 + 3 / 4
..
1 / 2 / 3 / 4
(parenthesis can be ignored for this program)
This is what I have so far, but I don't know how to continue:
import java.util.Scanner;
public class ArithmeticComputation{
public static void main(String[] args) {
Scanner stdin = new Scanner(System.in);
int num1 = stdin.nextInt();
[Code] ....
I'm looking for a method that allows me to assign char into actual operators, so that I can loop through all the computation.
Unchecked Or Unsafe Operations While Compiling Program?
Jun 30, 2014String filename="C:UsersRajashekarDesktopfwfwdSoftware Failures1_Test.txt";//Input Files
String data;
public ArrayList<String> value=new ArrayList<String>();
public void read() throws IOException{
File f = new File(filename);
[Code] ....