class A
{
public final int Add(int a,int b) {
return a+b;
}
}
class B
{
public static void main (String args[])
{
System.out.println(Model.Add(5,10));
}
}
This is what I have. I'm not sure if this even makes use of a final method. But when I run it I get an error saying cannot find symbol for line 13.
I am trying to write a program which asks the user to enter two numbers and then do the arithmetic operation based on user's input . No compiling errors but when I run the program I keep getting "StringIndexOutOfBounds" error .
class arithmetic {
public static void main(String[] args){
Scanner in = new Scanner(System.in);
int ent1 = 0;
[Code]....
I am able to perform column operation but not able to perform row operation because i am not able to store data say a 2 matrix [][]. I need to store the data into a 2-D matrix. Here is my code:
Java Code:
import java.awt.List;
import java.io.BufferedReader;
import java.io.FileReader;
import java.util.ArrayList;
import java.util.Scanner;
public class colRowRead {
[Code] ....
I tried something like that:
for(int i=0; i<rows; i++) {
for(int j=0; j<cols; j++){
matrix [i][j]=textFile.get(i).split(" ");
//System.out.println(matrix[i][j]);
}
}
*/ mh_sh_highlight_all('java');
File col.txt is like this:
Java Code:
5 9 7 1 5
3 6 8 6 8
4 6 7 8 9
9 8 3 5 7 mh_sh_highlight_all('java');
I am somewhat of a java newbie (learned it awhile back and just getting back to programming some again.) I have a text file of data much larger than this, but here are the first ten rows and first 10 columns.
39755320111041730140.633038085-2.117082366149.069997
39850320111041730150.633038085-2.117082511148.309997
39955320111041730160.633037998-2.117082293149.509997
40055320111041730170.633037945-2.117082351149.239997
.......
I can read and write all the data back out to files. But I am not sure about a few things.
First would it be best to use BufferedReader and OutputStream such as:
public static void main(String[] args) throws IOException {
BufferedReader bReader = new BufferedReader(new FileReader ("testdata.txt"));
BufferedOutputStream bytesOut = new BufferedOutputStream(new FileOutputStream ("outfile.txt"));
Second, I was then going to initialize an array but I might have 30 or more columns of data, of which I might perform and output only 10 columns to my output.txt file so is this a good way?
Third, I only want to perform operations (such as average the data, convert units or multiply two columns together) on 10 of the 30 plus columns and print out results to output.txt file. For example, In testdata.txt file above, I want to skip first seven columns. I then want to take column 8 and multiply by 100 then divide by 3 and output result to output file. I want to do same for column 9. Column 10 I want to multiply by different number (by 3.5).
How do i go about developing a simple arithmetic tester program which can be used to support young children improve their arithmetic skill. The program should accepts string data for the player's name and the number of questions they want to try, which will be entered by the user. The program should take in the following inputs from the user:
The name of the player, so that the game can refer to them by name in messages. The name must be between 2 and 20 characters inclusive.
The number of sums that the user wants to attempt. This number must be a whole number, and be between 2 and 50 inclusive.
The program must check that the values entered fall within the valid ranges. The program must also check that no empty strings are entered for names.
Once the player has entered their name and the number of questions they want to attempt, the game begins. The program must generate sums for the player.
The program should generate one question at a time and display the question for the user. The questions must involve two numbers and be either a multiplication, division, subtraction, or addition. For example, the following are all valid questions:
3 * 4 = ?
8 / 2 = ?
7 + 1 = ?
9 - 8 = ?
The first number, second number, and arithmetic operator (multiply, divide, add, subtract) should all be chosen randomly, the program should Generate a new random number for each of the three parts of each sum. this requires you to choose one of the four symbols based on which random number is returned.
A few checks must be carried out before a generated question is displayed to the user. If the question is an addition question, no checks are required. If the question is a multiplication question, no checks are required. However, checks are required for subtraction and division sums.
If the question is a subtraction question, the program must check that the second number is equal to or smaller than the first number. Whilst the second number is larger than the first number, new numbers should be generated.
I want to catch the exception in my program is the below way:
class Temp
{
public static void main(String s[])
{
try
{
int x=10/s.length;
System.out.println(x);
[Code] ....
I am expecting my program should give output as "java.lang.ArithmeticException: / by zero" but is giving
Temp.java:11: error: ')' expected
catch (ArithmeticException e | ArrayIndexOutOfBoundsException e)
^
Temp.java:11: error: ';' expected
catch (ArithmeticException e | ArrayIndexOutOfBoundsException e)
^
Temp.java:16: error: 'catch' without 'try'
catch (Exception e)
^
Temp.java:22: error: reached end of file while parsing
}
^
4 error
which when user enter a number then will display how many * in a line .Produce a line: ***** But my code only show 1 * there... what wrong with it ?
import java.util.Scanner;
public class display {
public static void main(String args[]) {
int i,n = 0 ;
[Code] ...
a. Create an application named ArithmeticMethods whose main() method holds two integer variables. Assign values to the variables. In turn, pass each value to methods named displayNumberPlus10(), displayNumberPlus100(), and displayNumberPlus1000(). Create each method to perform the task its name implies.
b. Modify the ArithmeticMethods class to accept the values of the two integers from a user at the keyboard.
I am having trouble using the equals method to return the appropriate value using standard arithmetic.
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.FlowLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
[Code] ....
I know that "inText.setText(Integer.toString(secondOperand));" in the code is wrong, I just don't know the right code...
Write a program to simulate the operation of a simple robot. The robot moves in four directions: Forward, backwawrd, left, and right. The job of the robot is to move items and place it in the right slots in each station. There are 8 stations plus the pickup station. Pick up station is the initial start where the robot picks the items. 8 items can be placed on each station. The nearest station must be filled before placing items on the next station. The items are marked with identification or serial numbers. The items with odd serial number go to the right and items with even number go to the eft. The last slot, number 7 is reserved for light items which are less than 80kg. The serial number is a five digit number, the MSB digit 5 indicates that the product must be placed in the fifth station which is keeping the product at 20 degree F.
View Replies View RelatedMy teacher has asked me one question that "What is difference between the final method and static method".
View Replies View Related1 Can method declared as final be overridden and overloading ?
2 if A is static sub class of B. how to access a method in class A ?
This has three different classes in a package and the program itself is supposed to read and perform operations obtained from a txt file. However, I'm not even sure how to get it to perform the operations from the text file. I know that it can read the file as I was able to get the program to print the text found in the file when I ran the program with a test print to make sure that all content was being read. However, I am clueless when it comes to how to get the program to look at the text as commands.
Here is the piece of code that I am not sure where to go from as far as telling the program to read the text and perform the tasks listed.
public static void doTVoperations(){
File operations = new File("operations.txt");
if(operations.exists())
try{
Scanner n = new Scanner(operations);
while(n.hasNext()){
String readOperations = n.nextLine();
String [] command = readOperations.split("[
]");
}
n.close();
}
catch (FileNotFoundException e){
System.out.print("Error...TV in need of repair!");
}
I am using findbugs and PMD as a code analyser. I am keep getting warnings to use local variables and method parameters as final.
I want to know if its a good practice to keep them final or what to do?
Sometime i have a private method which is 1 line longer. Sometime it is annoying to use final.
this code won't compile because selected row must be declared as final because of it being defined outside the window listener. Is their anyway around this? If I make it final the first time that the variable is called it keeps it starting value until the GUI is closed.
butEdit.addActionListener (new ActionListener () {
@Override
public void actionPerformed (java.awt.event.ActionEvent evt) {
int selectedRow = table.getSelectedRow ();
final String [] values = custTableModel.getRowValues (selectedRow);
[code]....
Created a java.sql.connection object. Refering those obj inside public void run() { } If i declare as final inside a method, i can't refer those outside method due to scope. Cannot refer to a non-final variable dbConnObj inside an inner class defined in a different method...
View Replies View RelatedI want to create a final array with final elements
{code}
final int[] array = {0, 1, 2, 3, 4, 5};
{code}
But here only the reference of the array is final , not it's elements ... So how can I do that??
Many classes calculate a final grade by using a weighted scoring system. For example, "Assignments" might be worth (weighted at) 40% of your final grade. To calculate the portion of the final grade contributed by the Assignments category, the teacher takes the average of all assignments in the category and multiplies it by the weight (40%). So if a student averaged 90% on all assignments, the teacher would take 40% of 90%, or 36 as the weighted average score for the assignment portion of the the final score. The teacher then calculates the weighted average score for each of the other categories (Quizzes, Midterm Exam, Final Exam, etc.), adds them all together to come up with the final score, and assigns a letter grade based on that score.
Write a Java program that allows the teacher to calculate the grade for a student.
Specification :
Prompt the user to enter the Student ID number, first name, last name, and the average score for each of the following categories:
Assignments (worth 50%)
Quizzes (worth 20%)
Midterm Exam (worth 10%)
Final Exam (worth 20%)
Calculate the weighted average score for each category and the total score for the student. Next assign a letter grade as follows:
90 - 100 = A
80 - 89 = B
70 - 79 = C
60 - 69 = D
59 and below = E
Print the results in the following format:
Name: [Last Name], [First Name]
Student ID: [Student ID]
Assignments: [weighted average]
Quizzes: [weighted average]
Midterm Exam: [weighted average]
Final Exam: [weighted average]
Total: [total score]
Final Grade: [letter grade]
Prompt the user to either enter another student or to quit. Continue the process until the user chooses to quit.
I almost done everything but I cant calculate a total score for the student or Assign a letter grade based on the score!!!!
package teacher_grade;
import java.util.Scanner;
public class teachergradeing {
public static void main (String[] args) {
//Scanner objective
[Code] ....
Which two method HashMap key object should implement?..
View Replies View Relatedso, i have a problem in implement method named viewAllFactor(User us,ResultSet rs)when i call this method using <T> like objet dont work because T obj is nulli ask if i can try something to have a good result.
I have 2 classes BaseDao<T> (DAO Pattern) and Class User extends from BaseDao
this is the code
package appweb.core;
public abstract class BaseDao<T> {
public ArrayList<T> viewall() {
ResultSet rset = null;
ArrayList<T> listAll = new ArrayList<T>();
String sql = "SELECT* FROM "+ this.tableName;
System.out.println(sql);
try {
[code]....
if i call a class that implements an interface the method inside the interface will be triggered automatically by the compiler or happens only in the observer pattern? i keep simple to be surr the message came across, a typical example would be a listener on a button, or a collection that calls comparator)
View Replies View RelatedImplementing the add(int i, E o) method for a SinglyLinked List.
public void add(int i, E o)
// pre: 0<=i<= size()
// post: adds ith entry of list to o
I have a drop-down which contains the four sections simple buttons(filters). When click any of these buttons some settings are applied. I have successfully auotmated it using simple if else and switch but in that case i have to use 8 parameters(8 are the number of button)
public void editFilters(WebElement filter1, WebElement filter2, WebElement filter3, WebElement filter4,WebElement filter5,WebElement filter6,WebElement filter7,WebElement filter8 String edit, String expectedColour) {
switch (edit) {
case "selectFilter":
if (filter1 != null) {
[Code] .....
But want to make it more effective by using hashes. I do not want to use 8 different parameters to perform action on the respective button.
So now what i want to implement.
Create a method in which i pass the parameter1 as hash and 2nd parameter as 0 or 1, 0 means unSelectFilter and 1 means select the filter.
With parameter 1, in code i want to pass the name or xpath or anything else for any number of filters , that those filters names should be stored into that hash and then by passing 0 or 1, i can select/unselect those filters.
if some of you worked with Unity Game engine (C#) the idea is that game has main loop and once per cycle it call for example Update() method in all objects which implement certain interface.
I would like to repeat such pattern in Java for another another program, not even game related, but I would still need a main loop and event driven behaviour with async call backsSo question is how to implement the fallowing scenario:
Imagine i have interface which implement some methods and one of them is Execute()
I have the main controller class which implement main loop, also multiple other classes which implement the same interface with method Execute(). How can i call this Execute() method on all objects which implement that interface each loop cycle?
Should i keep and track reference of each object which was implemented with this interface and go through inner "for" loop trough each reference and call manually Execute() method in each of them?what if each object implementing interface have to run Execute() method simultaneously? in parallel independent from each other?
Referring back to Unity engine and their Update() method - there is exactly the same situation:you can have multiple objects with script attached, thats script implement interface which has multiple methods and one of them is Update() and once per cycle all objects with that Update() method will be executed in parallel independently
So I created an interface which has the method
int getCalls();
I am trying to implement this method in another class but I'm not sure how to do so. My attempt is:
public getCalls(){ return getCalls(); }
When I run the program it sends the following exception:
Exception in thread "main" java.lang.StackOverflowError
at FibonacciForget.getCalls(FibonacciForget.java:14)
and it highlights the [return getCalls();] part.
What is the correct way to implement the getCalls() method?
Let's say we have situation like this:
abstract class A
class B extends A
class C extends B
class D extends C implements SomeInterface
I'm trying to implement a method "doSomething" declared in SomeInterface in class D. While trying to call doSomething in main I get the error message ”The method doSomething is undefined for the type B”
This is my code i main:
B container = new D("1,2,3,4,5,6,7,8");
System.out.println(container.doSomething());
I need container to be an object of type B, because it goes later into a list of type B. According to what I've been told, the only file I need to edit to make this work is class D.