Evaluating User Input For String Or Int
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.
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Apr 13, 2014
I trying to get this code to get user input instead of reading from a hardcoded array. I'm getting compile errors while trying to get user input. Here's some of the code:
Java Code: // BubbleSort Java
// compile with: javac BubbleSort.java
// run with: java BubbleSort
[Code]....
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Jul 29, 2014
I'm having an issue with my program that needs 2 lines of input when I only want one. First I call Scan.nextLine(); to fetch a word. Then I want Scan.findInLine(word).charAt(number); to scan the string word for a letter instead of having to put another line in the console. How do I make Scan.findInLine(word).charAt(number); scan a single String instead of scanning input typed by the user?
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Jan 20, 2015
I am having trouble with getting a user input once they enter it in to a JTextArea and then storing it in to a string value. See, I wanted the user to enter an answer in to the JTextArea, and then once I store it in to a string value, I would be able to use it later. I wanted to after storing the variable to print it on to a JLabel, but nothing is showing up... Heres my code.
static String usera[]= new String [10];
for (int i=0; i< usera.length; i++) {
//These are the JTextArea names
usera[0]= Question1.getText();
usera[1]= Question2.getText();
[Code].....
I already initialized the JLabels earlier in my code, and I did not feel the need to post all my code here. This is where I am trying to get the string variable and then printing it out.
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Jul 26, 2014
I have the code below that just keeps getting the user's name and displaying it until the user enter's an empty string. Well, to simulate that, I just hit the keyboard instead of entering any name but for some reasons I am not seeing in my code, the programme just keeps looping.
System.out.println("Enter your name :
");
Scanner st = new Scanner(System.in);
while(st.hasNext()){
System.out.println("Enter your name :
");
String name = st.nextLine();
System.out.println(name);
if(name==" ") break;
}
System.out.println("you are out of the while loop now!!");
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Apr 24, 2014
So this application gets input from the user and converts it into a string. It then uses various methods to set instance variables of this class and ends up printing those classes to display information to the user about that products.
package javaapplication5;
import java.text.NumberFormat;
import java.util.Scanner;
public class Product
{
private String product;
private String description;
private double price;
[Code] ....
I am getting a logical error. My output is this:
Enter a product for information. Choose either Java or C++
java
Prduct: null Description: null Price 0.0
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Jul 8, 2014
I am trying to make a program that calculates the change due in dollars and cents. The user inputs both the amount due and the amount tendered. My program only works with whole numbers?
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Apr 16, 2015
I made a guess a number program but I am having issue figuring out a way that when a user enter's in nothing for the program to spit out a message saying "hey entering nothing doesn't work try again" then ask for input. I have done some research and from what I have found is to read the input in as a String rather than int, and use something like Integer.valueOf() to get the integer value but I am completely lost on how to apply that to my program here is my code
//import statements
import java.util.*; //for scanner class
// class beginning
public class Guess {
public static void main(String[] args ) {
//Declare variables area
int guess, secretNumber = (int) (Math.random() * 10 + 1), lowGuess,highGuess;
[Code] ....
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Dec 9, 2014
My assignment is to create a hangman game. One of my first difficulties with it is how to scan the string for an input supplied by the user.
Here is my method:
//Guesses that character c is in the secret word.
//Updates all instance variables accordingly,
//and returns true if c is present in the secret word.
public boolean guessCharacter(char c){
}
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Apr 7, 2015
The project is a program that allows the user to enter students and enter grades for each student. One of the requirements is that if there is already a grade stored for the student that it will display the previous grade. IF the user then enters a new grade the new grade will be stored. IF the user simply presses enter (enters an empty string) nothing is done. I have everything working except for the requirement of doing nothing if the user enters an empty string. If I just press enter at this point I get a NumberFormatException.
The below code is a method "setTestGrades" from the student class. This method iterates through each student object stored in an array list and then checks if there is a previous grade (Requirement# unset grades have to default to -1) before allowing the user to set a new grade.
public void setTestGrades(int testNumber) { //Sets the grade for the specified test number for each student in the arraylist.
testNumber -= 1;
Scanner input = new Scanner(System.in);
for (int i = 0; i < studentList.size(); i++) {
System.out.println("Please enter the grade for Test #" + (testNumber + 1) + " For Student " + studentList.get(i).getStudentName());
[code]....
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Mar 30, 2014
I am creating a simple Symptom Checker application. The problem I have is that I'm trying to retrieve user input (JTextField) by comma's using StringTokenizer which contacts the database for a result which matches the user's input (SELECT * FROM DIAGNOSIS WHERE ?, ?, ?) . It successfully finds the correct result however only in a particular format. Not different combinations....
for example, if I enter say within the JTextField: "tearful, nausea, lack of motivation" it will find the result successfully (as that is how it is formatted within the particular column (in the database table) i wish to display a result from) however, if i enter a different combination of these symptoms: "nausea, lack of motivation, tearful" - it will not find any result. I'm very unsure how to make it work regardless of what is inputted first, second or last.
Here is the code:
public void actionPerformed(ActionEvent e) {
try {
String abc = fieldsymp1.getText();
StringTokenizer str = new StringTokenizer(abc);
while (str.hasMoreTokens()) {
str.nextToken((", ")).trim();
[Code] ....
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Sep 23, 2014
I need to design, implement, and test a program to input and analyze a name. The program begins by retrieving a user input string from the keyboard. This string is intended to be the user's name. These are the errors we have to search analyze the user input for: No blanks between names firstName and lastName, Non-alphabetic characters in names, Less than two characters in first name, and Less than two characters in last name. Each of these errors must be thrown. All exceptions must be derived from a programmer-defined class called NameException. Each exception should use a detailed message to differentiate among the file types of errors.
This is the format of my NameException class, is the format itself correct? I will fill in the details of each exception I am just wondering if that is how I should set it up.
public class NameException extends Exception {
private String firstName, lastName;
public NoBlanksException(String firstName,String lastName) {
}
public NonAlphabeticalCharactersException(String firstName, String lastName) {
[Code] .....
I was told not to try and catch thrown errors in the main method, would I just create another method in the Driver class to take care of that then?
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Nov 11, 2014
I am writing a code in which a user inputs data as a string and that data must be verified as a valid number. A valid number is anything from 0-100. Then all valid numbers are converted into double numbers.
I am having trouble in how to write the validation part of the code.
Is it suppose to be an if, else statement? And if so how is it suppose to be validated?
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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?
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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.
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Apr 9, 2014
Write a java program that will ask a user to input grades until the user inputs the sentinel value -1. The program should test each input to determine whether 0<=grade<=100. If the grade entered is within this range, the program should print "Grade accepted;" if not, the program should print "Invalid input".
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Nov 4, 2014
I have been struggling with this program for weeks. This program is supposed to take a user's inputted odd number and then print out all prime numbers lower than that number.
public class PrimeNumber
{
Scanner scan = new Scanner(System.in);
int userNum;
String neg;
public void getUserNum()
[code]...
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Apr 9, 2015
Where do I input this segment?
Scanner user_input = new Scanner( System.in );// This line goes at the top with the other global variables
public void getUserInput(){
System.out.print("Enter litres: ");
litres = user_input.nextDouble( );
System.out.print("Enter mileage: ");
mileage = user_input.nextDouble( );
System.out.print("Enter speed: ");
speed = user_input.nextDouble( );
[Code] ....
This is my client file.
class Client{
public static void main(String []args){
Bike R1=new Bike(5.0, 60.0,30.0);//create bike object with params
Bike R2=new Bike();//without params
System.out.println(R1.increaseSpeed());//calling methods
System.out.println(R1.maxDistance());
System.out.println(R2.increaseSpeed());
System.out.println(R2.maxDistance());
}
}
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May 22, 2014
I'm having trouble with the last few lines of the code. It's supposed to take a replacement string entered by the user and print out the new string. For some reason it's now allowing me to enter a replacement string
import java.util.Scanner;
public class Project02 {
public static void main(String[] args) {
Scanner keyboard = new Scanner(System.in);
System.out.print("Enter a long string: ");
String lString = keyboard.nextLine();
[Code] ....
Output:
Enter a long string: the quick brown fox jumped over the lazy dog
Enter a substring: jumped
Length of your string: 44
Length of your substring: 6
Starting position of your substring in string: 20
String before your substring: the quick brown fox
String after your substring: over the lazy dog
Enter a position between 0 and 43: 18
The character at position 18 is x
Enter a replacement string: Your new string is: the quick brown fox over the lazy dog <------ isn't taking user input
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Nov 13, 2014
I have been coding in my class at school (Grade 11 Computer science) and i just downloaded the program on my computer at home, unfortunately i cannot access my computer notes at home and i also dont remember certian specifics of coding, so my question is how would i get user input to create a program. The comments are the parts i dont remember. (I am trying to slowly build my memory with this stuff)
Here is my code so far:
import java.util;
[highlight=java]
public class hello_world {
public static void main(String[] args) {
string name;
//WHAT DO I PUT HERE????
[code]....
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Apr 19, 2014
I'm working on creating a dice game and getting the users input is giving me a really hard time. I have the main game working but this part I'm stuck on. The problem is that it's not giving me the chance to enter the second input when I ask for the game.
//Create Scanner object
Scanner keys = new Scanner(System.in);
//Get chips
[Code]....
*****This is what I get when I run it
run:
How much money would you like to change? 50
You now have $50 in chips.
What game do you want to play? You did not pick dice.
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Oct 11, 2014
Is there a way you can control user input?
For example, is it possible to only allow the user to enter digits?
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Feb 4, 2014
I have been given a piece of work to do for College that requires me to format user input. For example: This is an example of text that will have straight left and right margins after formatting
will transform into:
This..is..an.example
of..text..that..will
have..straight..left
and...right..margins
after.....formatting
The user inputs the width, in the case above being 20. Each line has to therefore be 20 characters long. All spaces are to be replaced with full stops.
This.is.an.example.o
f.text.that.will.hav
e.straight.left.and.
right.margins.after.
formatting..........
public class Main {
public static void main ( String args[])
[code]....
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Jul 2, 2014
Goal is to get user input and sum together. I've tried it different ways. This is the one with the least amount of problems.
Exception in thread "main" java.lang.RuntimeException: Uncompilable source code - Erroneous sym type: java.lang.Integer.parseInt
ArrayList<Integer> leftCU = new ArrayList<>(); {
System.out.println
("Please enter one at a time the number of CU's for each class that is left to complete. Enter Q when done.");
leftCU.add(in.nextInt());
[Code] .....
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Jan 9, 2015
I am trying to get user input for a char value and am having some difficulty getting input for a char value.
Java Code:
//imports packages
import java.io.*;
import java.text.DecimalFormat;
class ModuleCulminatingTask {
public static void main (String args []) {
//declares variables
float var3, var4;
long var5 = (int)(Math.random()*10);
[code]....
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Apr 10, 2014
I'm not sure what is wrong with my code:
import java.util.Scanner;
public class Main {
int age = 0;
System.out.println("Enter your age: ");
// Read in values
age = in.nextInt();
}
The in is underlined, telling me "cannot find symbol"
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