Evaluating Expression Without Brackets
Feb 3, 2015
I am working on a program to evaluate an expression without brackets using stacks. I am getting the following error :
3+1*2+4
-2.0
Exception in thread "main" java.util.EmptyStackException
at java.util.Stack.peek(Stack.java:102)
at java.util.Stack.pop(Stack.java:84)
at assignment2.Evaluate.main(Evaluate.java:42)
I imported the Stack from java.util.Stack
package assignment2;
import java.util.Scanner;
import java.util.Stack;
public class Evaluate {
public static void main(String[] args) {
Stack<String> ops = new Stack<String>();
[Code] ....
What is causing this error? Does it look like the program should function as intended?
View Replies
ADVERTISEMENT
Jan 14, 2015
I have to take a users input. The general gist of the problem is I want to convert a decimal number entered by the user inputs into it's binary equivalent....the conversion part I know how to do.
I'm stuck at the user input phase. If the user inputs a decimal number within the correct range (lets say between 0-5000 for this example) the conversion goes ahead as planned and the program outputs on the screen the binary equivalent.
If on the other hand the user inputs a number outside of this range ... OR a String OR and empty space, an error message is given and the user is asked to try again. I don't know how to handle it if the user enters the different types...int or String.
View Replies
View Related
May 12, 2014
I am given the task to create a program that evaluates infix expressions using two generic stacks, one operator stack and one value stack.
This is my GenStack.java file:
import java.util.*;
public class GenStack<T>{//T is the type parameter
private Node top;//top of stack
public class Node {//defines each node of stack
T value;
Node next;
[Code] ....
I'm having trouble with the eval and apply methods. The eval method doesn't appear to pickup ')' characters, like it doesn't even see them.
View Replies
View Related
Oct 22, 2014
At this moment in time my program compiles and runs as I want it to, but when I look at my code I see that my While Loops braces are placed inside my Try Block. When I move these braces outside of the Try Block, next to the WhileLoop, the program doesn't run like I want it to.
Likewise, when I place the While(answerIsCorrect) inside the Try Block, it doesn't work like I want it to either.
Also, my problem is on Lines 17 and 18.
import javax.swing.*;
import java.util.Random;
public class SwingInputExample
{
public static void main(String args[])
{
int firstNumber=0;
int secondNumber=0;
int correctAnswer=0;
String studentGuess = null;
[Code] ....
View Replies
View Related
Feb 9, 2015
I'm trying to get my output to be displayed without the brackets.The output looks like this
22 ([1, 2, 11])
33 ([1, 3, 11])
44 ([1, 2, 4, 11, 22])
55 ([1, 5, 11])
66 ([1, 2, 3, 6, 11, 22, 33])
77 ([1, 7, 11])
But I want it to have no brackets displayed so it looks like this
22 (1, 2, 11)
33 (1, 3, 11)
44 (1, 2, 4, 11, 22)
55 (1, 5, 11)
66 (1, 2, 3, 6, 11, 22, 33)
77 (1, 7, 11)
import java.util.ArrayList;
public class Palindrome {
public static void main(String[] args) {
int e = 0;
// palindromic composite number
int drome = 0;
[Code] ....
View Replies
View Related
Oct 3, 2014
I have spent the past 12 hours on it and have gotten no where. I need to create a program that will calculate different tax brackets. I have tried all combinations I can think of and can't get it to work!!! I am literally about to go insane! I need the program to calculate tax will be 1% for anything up to $50000. If the tax is over $50000, you keep that 1% of $50000 and then add the remaining. So for an income in the second range, it would be 1% of $50000, and then 2% of (income - $50000). This then continues for each range.
The problem I'm having is getting it to display the correct interest rates. I am not asking for you to write it for me. I want to learn. But at this point I have exhausted all resources available to me.
import java.util.Scanner;
public class Project3taxinfo {
public static void main(String[] args) {
final double RATE1 = 0.01; //1% tax on the first $50,000
final double RATE2 = 0.02; //2% tax on the amount over $50,000 up to $75,000
final double RATE3 = 0.03; //3% tax on the amount over $75,000 up to $100,000
final double RATE4 = 0.04; //4% tax on the amount over $100,000 up to $250,000
final double RATE5 = 0.05; //5% tax on the amount over $250,000 up to $500,000
final double RATE6 = 0.06; //6% tax on the amount over $500,000
[code]....
View Replies
View Related
Apr 10, 2009
When you "system.out.print(arraylist)" an arraylist, it will give you something like [item1, item2].
Im wondering how I can remove the "[" and "]" brackets fromt he printout, or even if i pass it in as another variable.
View Replies
View Related
Jan 16, 2014
I'm using this try statement to check for errors in input in my Tic Tac Toe game. The problem I have having is I don't understand why this error is happening. It's preventing my code from compiling. I've tried inserting an else statement and multiple brackets at various places with no success.
Java Code:
public void play(){
Scanner input = new Scanner(System.in);
int row, col;
char currPlayer = 'X';
[code]....
View Replies
View Related
Oct 21, 2014
Im trying to do this program but I keep getting Empty Stack Exception when I execute balancedBrackets. I know that push and pop methods works, but I'm not so sure if my logic for balancedBrackets is correct.
public void push(T t){
if(this.top+1==this.size){
duplicateCapacity();
}
else{
top++;
arr[top]=t;
[Code] .....
View Replies
View Related
Oct 12, 2014
The program i am working on is to take string from the user which should be a phone number then it will return true or false based upon the method that checks to see if it meets the criteria of a certain format if does not it will return false otherwise return true. I am working on a if/else structure that will print this number is valid if it meets the criteria of the method i previously mentioned or return the number is not valid if it is false. the logic of the expression i put in the parentheses of the if/else statement. This is what i have so far:
if(){
System.out.println("The phone number is valid");
}
else {
System.out.println("This isn't a valid phone number");
}
Do i need to compare it based upon the method that checks if it is true?
View Replies
View Related
Feb 27, 2015
I have a math expression in a String, that I want to split into 4 pieces as in the following example:
String math = "23+4=27"
int num1 = (23 STORES HERE)
int num2 = (4 STORES HERE)
String operator = (+ STORES HERE)
int answer = (27 STORES HERE)
Note that the operator can be either + - * /
View Replies
View Related
Aug 25, 2014
I have to match pattern like 76XYYXXXX mean x can be 4or 5 and Y can be 6 or 7. All x and y should be same .i.e. 764664444
View Replies
View Related
May 4, 2015
package com.example;
import com.example.domain.Admin;
import com.example.domain.Director;
[Code]....
View Replies
View Related
Apr 23, 2015
So everything in my program is working EXCEPT when it comes to calculating the result. I am supposed to evaluate the expression using postorder traversal to return the answer. I am honestly not sure how I would get the postorder traversal to return the answer to the expression since the only thing we really went over was how it re-ordered the expression so that it would end in the postorder/postfix order. Anyways, currently the way that I have the public int evaluate(Node node)method set up is giving me a result of 0, which obviously is not correct.
Here's the section that I'm having issues with:
public int evaluate(Node node){
if(node.isLeaf()){
return Integer.parseInt(node.value);
}
int result = 0;
int left = evaluate(node.left);
int right = evaluate(node.right);
[code]....
View Replies
View Related
Jul 30, 2014
How that's possible
import java.util.*;
public class Stars {
public static void main(String[] args) {
line (13);
line (7);
line (35);
System.out.println();
box(10,3);
[Code] ....
View Replies
View Related
Jan 17, 2014
I am currently enrolled in my first Java class. I have taken C# in the past so I've messed with some regular expressions, but I am having trouble finding a good website for Java. Is the syntax the same?I want to create a regular expression to only allow the following characters: c C f F [and any 1-3 digit number].
View Replies
View Related
Aug 20, 2014
I am getting the error "Line 54, illegal start of expression". Line 54 is where my "for" starts. It was running ok earlier, now I can't get this error to go away?
public static void main(String[] args) {
double salary;
double commission;
double totalSales;
double annualComp;
double salesTarget;
double incentive;
double accel;
double incentive1;
double notAccel;
double increment;
[code]....
View Replies
View Related
Dec 15, 2014
So my EL expressions in my jsp are not taken into account in my project. It was working fine when I was using DAO but I switched my project to ORM using the annotations. Using Tomcat in the first place and now JBoss 7.2. Anyway take a look because I really don't understand what I have to do.
When I acces the page I create I get this : OyN3K.jpg while I'm supposed to have a form.
Example my connection jsp:
<title>Connection</title>
</head>
<body>
<form method="POST" action="connection">
<fieldset>
<legend><b>Connection</b></legend>
<c:import url="connectionForm.jsp" var="importedData"/>
[Code] ....
I don't think it's an error in my code but more or less a configuration problem. Btw I don't think it's a problem in my url since when I put a wrong one I've an error telling me it doesn't find the jsp file. That said it's clearly the ${} not being taken into account.
Here is the download link of my project: lab.zip
View Replies
View Related
Mar 16, 2015
I have a string "We have 7 tutorials for Java, 2 tutorials for Javascript and 1 tutorial for Oracle" I need to replace the numbers based on the below condition.
if more then 5, replace with many
if less then 5, replace with a few
if it is 1, replace with "only one"
below is my code, I am missing the equating part to replace the numbers
private static String REGEX="(d+)";
private static String INPUT="We have 7 tutorials for Java, 2 tutorials for Javascript and 1 tutorial for Oracle";
//String pattern= "(.*)(d+)(.*)";
private static String REPLACE = "replace with many";
public static void main(String[] args) {
// Create a Pattern object
[Code]...
View Replies
View Related
Apr 17, 2014
I have written below regex for two lines.
String LN1Pattern = "^((?=.{1,35}$)(/([A-Z]{1,5})(|(//[a-zA-Z0-9]+))))$";
System.out.println("/ABC//FGhiJkl012345".matches(LN1Pattern));
String LN2Pattern = "^(|((s+(//[a-zA-Z0-9]{1,33})){1,2}))$";
System.out.println("".matches(LN2Pattern));
s+ is a newline character.
But when I combines both as below, its not giving me expected result.
^(((?=.{1,35}$)(/([A-Z]{1,5})(|(//[a-zA-Z0-9]+))))(|((s+(//[a-zA-Z0-9]{1,33})){1,2})))$
For string "/ABC//FGhiJkl012345
//abCD01EF02" - returns False. Expected is True
I think there is some problem in lookahead placed.
View Replies
View Related
May 28, 2014
I understand how mixing expressions of different data types can result in an error if the assigned variable is not the same data type. But I don't understand how the below causes an error:
short totalPay, basePay = 500, bonus = 1000;
totalPay = basePay + bonus; // This causes the error
500 + 1000 = 1500. 1500 falls within the short parameters. If basePay, bonus, and totalPay are all short, as well as the resulting equation, how is this erroring?
View Replies
View Related
Mar 7, 2015
I have a variable <c:set var="var1" value = "myvalue" /> , I want to pass var1 as <%= new customclass().method1(var1) %>.what is the syntax to pass this value.
View Replies
View Related
Mar 17, 2014
Lines 7 , 10 ,13 .... All have a Illegal Start of Expression error.
[color=blue]private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
Random rd = new Random();
int random = 0;
random=rd.nextInt(6)+1;
switch(random){
[Code] ....
View Replies
View Related
Feb 4, 2015
I 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.
View Replies
View Related
May 21, 2014
In my Icefaces 3 application I have a ManagedBean ancestor that defines common attributes to those they spread it. Including CSS styles to be apply at the menu as icons depending on whether they are selected or not. Classes that extend the CommonMBean class define styles. My question is what do I have to put in the language experssion styleClass to tell him that the getter to use is that of the parent class.
CommonMBean.java
package com.omb.view;
public class CommonMBean
private String menu1Css = "";
private String menu2Css = "";
[code]....
View Replies
View Related
Mar 19, 2014
In the servlet class I have:
String name = "James Bond";
Session.setAttribute("name", name);
Why is the attribute name and attribute value the same in all the books I've read. I know one is a string literal and one is an object but must it be the same?
Second thing I'm confused about... let's say I change the servlet code to
String name = "James Bond";
Session.setAttribute("hisname", name);
When I try to access it using JSP:
${sessionScope.name}
it works fine. So what is the point of the first argument in Session.setAttribute() ?
View Replies
View Related
