When I try to call an object it can't find the symbol in the argument list. NetBeans says that it cannot find the movieCategory symbol when I try to call it. When I compile it to test a popup comes up that states "One or more projects were compiled with errors. Application you are running may end unexpectedly. I ran it anyways and everything runs up to the point of where it should call the object.
At this point it should get the Movie object and run the code within that, but if I put one of the categories it throws. "Exception in thread "main" java. lang.RuntimeException: Uncompilable source code - Erroneous tree type: <any>at MovieApp.main(MovieApp.java:33)Java Result: 1"
From my understanding to call an object it requires objectName.methodName(argumentList). Here is my Main method
/**
*This application will store a list of 100 movies and display them by category
*/
import java.util.Scanner;
public class MovieApp
{
public static void main(String args[])
{
//Displays <code>String</code> welcome message
System.out.println("Welcome to the Movie Application.");
System.out.println("There are 100 movies in the list.");
System.out.println("What category are you interested in?");
System.out.println();
The idea is to create a program to add plants and retrieve plants from a Nursery. I created a class with the properties of the plants and also there is the class an Array list to keep track of the plants entered ( they will have to be printed later) (I am not too sure if adding a public class there is the best option.
The program will allow the user to pick and action and from there the code will do something. I don't want to have all the code inside 'main' The problem is in line 114.This is what I have so far.
Java Code:
package plant.nursery; import java.util.ArrayList; import java.util.Scanner; /**Class to create a plant for a nursery. public class PlantNursery
I have been reading about methods and I do have a beginner level understanding on how they work. I was trying to mess around and make a dog calculator using methods. I ran into a small snag; I cannot get the method to call to the main or the program to compile correctly. The first code below is the original. To me it looks like (based off of some examples I looked at) there should be no problems, but NetBeans gives me a few errors. 1) line 8- "cannot find symbol, variable dogYearCalc; 2) line 18 illegal start of expression; and 3) line 22 - unreachable statement.
import javax.swing.JOptionPane; public class KrisExample { public static void main (String[] args) { double dogYears = 0; JOptionPane.showInputDialog (null,"Please enter you dog's age in human years:");
[Code] ....
Someone told me that I was calling dogYearCalc without any arguments in your main method. I take that to mean that I needed to add it to the main, so I did here:
public static void main (String[] args, double dogYearCalc) {
That got rid of my first error, but then when I tried to run the program NetBeans said that I have no main class, so switched back to the original program above.
I thought that when I calling the dogYearCalc method on line 10 was the whole purpose of using a method. It seems to me that putting it somewhere in the main is counter productive.
Can we recall the main method? I'm trying a code to recall main method (after the calling of JVM). I know this doesn't make any sense but I'm trying this just like that.
Code:
class derived { public static void main(String args[]) { System.out.println("Main Method class"); show(); } static void show()
This current one is to calculate a planes holding pattern. I have to write a method to prompt user to enter speed in knots, then it converts it to km/hr. Another method to calc. pattern width using the speed, another method to calc. pattern length, than a main method which would call and print out the speed in knots, speed in km, pattern width and length.My current problem is on the second method. It works in that I can enter the values and it gives me the correct answers, however it's asking me to enter the speed twice, instead of just once. Anything I try just results in errors and won't compile.
import java.util.Scanner ; //main method public class TitleRemoved { public static void main(String[] args) { double airSpeedKm = airSpeedOts () ; System.out.println("That speed is " + airSpeedKm + " km/hr.") ;
[code].....
I want my code to not only work, but be organized and easily readable as well, so I want to avoid bad habits.
I have a class for employees. This class has basic information for the employee but no real pay information. And 2 subclasses, one for employee's paid for hourly rates and one for those paid a yearly salary. Each subclass has their own pay() method, that calculates and returns their pay and extra fields relative to calculate that.
I'm just curious, if I do this and create an object for an hourly paid employee like so:
I've been trying to learn Java for the last 36 hours or so (after applying for a HTML/CSS job saying "Java knowledge preferred"), and decided to experiment a bit making a graphical tic-tac-toe game. I eventually managed to get that done and it's working. Working code below:
[Java] tic tac toe 1 - Pastebin
So, it works to an extent, however, the way I am capturing which cell is selected seems very sloppy, and would not work if the cells weren't squares or rectangles. So I made a copy of the project and restructured it adding the mouse event to the cells, but now I can't get JComponent to repaint. New code below:
tic tac toe 2 - Pastebin
Curiously, clicking triggers the action for all 9 cells, but I presume it's because I haven't bounded them making it think I've clicked all 9 simultaneously.
What I've tried:
Make the Cell class extend the game class and call this.repaint()- causes stack overflow.
Calling Game.GameState() within the cell clicking event and making that function static - compiler doesn't like calling repaint() inside a static function.
Making another class to make a clone of the Game object and then refresh- was never going to work....
Say I have two classes, Author and Book, and I have 2 author objects and 10 book objects. I would like to know how to do two things:
1) Make some sort of connection that makes clear that author X wrote books A, B and F. 2) Call a method from a book object that is connected to an author.
Seeing as I don't know which books will be connected to an author, is there some way to call a method of an object bases on a variable object name? Something like call the getFirstPage() method for every book that is linked to author X?
I've been writing classes over and over for school. So I create a class outside of my main class. I create a new constructor and then create objects from my main class. I hope that makes sense. So i use methods in that class to work with the object. So I have an object name I've created <dot> method name. So I can create objects and then use methods from the class, but I'm wondering can I create a method in my main class and use it on that object? I don't understand how to do that.
Exception in thread "main" java.lang.NullPointerExceptionat DogTestDrive.main(DogTestDrive.java:19)
Here is the source
class Dog { int size; String name; void bark () { if (size < 60) { System.out.println("Woof woof");
[code]....
Some background: I'm reading "Head first Java 2nd edition" and I'm going through the examples which is showing me how to change the state of an object. The original code looks like the code below, however the previous chapter went over creating array's of an object, so I created an array of the object "Dog" and wanted to re-write it this way. To my understanding, it should work but it's giving me that error when I execute it. The error itself isn't very clear, if I could get a line number pointed to, that would work.
class Dog { int size; String name; void bark() { if (size > 60) { System.out.println(“Wooof! Wooof!”); } else if (size > 14) { System.out.println(“Ruff! Ruff!”); } else { System.out.println(“Yip! Yip!”);
// Add range to Vehicle. class Vehicle { int passengers; // number of passengers int fuelcap; // fuel capacity in gallons int mpg; // fuel consumption in miles per gallon
// Display the range. void range() { System.out.println("Range is " + fuelcap * mpg);
[Code] ....
I'm compiling it in Eclipse and this continues to show in the console display
Minivan can carry 7. Exception in thread "main" java.lang.NoSuchMethodError: Vehicle.range()V at AddMeth.main(AddMeth.java:34)
In the process of creating a new class, I need to move my main method from the class SaveDate to the class DynamicTest. Below I have listed the code of both classes.The objective is to be able to run my program from the DynamicTest Class. I need understanding the process of moving my main method to a different class and creating an Object of a class and calling its method.
public class SaveData { private static final Map<String, Object> myCachedTreeMap = new TreeMap<String, Object>(); public static final List<String> getLines(final String resourceParam, final Charset charset) throws IOException{ System.out.println("Please get: "+resourceParam); if (myCachedTreeMap.containsKey(resourceParam) ) { // Use the cached file, to prevent an additional read.
I can call a child method from a main method. If I have a parent called "Assessment", a child called "Quiz", and another child called "test". Can I instantiate an object like Assessment a = new test(); and call a method in test.
I know the method can be called if I instantiate the test t = new test() but that defeats the purpose of inheritance...
I have a frame which I want to load an applet inside it. Here is the code i have in my main method:
MyApplet myApplet = new MyApplet(); myApplet.init(); myApplet.start(); javax.swing.JFrame window = new javax.swing.JFrame("myApplet"); window.setContentPane(myApplet); window.setDefaultCloseOperation(javax.swing.JFrame.EXIT_ON_CLOSE); window.pack(); window.setVisible(true);
But I get an exception:
Quote Exception in thread "main" java.lang.NullPointerException at java.applet.Applet.getCodeBase(Applet.java:169) at MyApplet.init(MyApplet.java:78) at Intro.main(Intro.java:68) Java Result: 1
What I want to do is have a label that is updated whenever an object gets some new, relevant data.The way you do it in Java looks different from the way we do it in Objective-C. In Objective-C, we have what's known as a protocol. An Objective-C protocol is almost exactly like a Java "implementation." In Obj-C, if I want the user to see the address of where he is, I can have an object that gets the information and invokes a view controller's method; at that point, the view controller would then take the data passed to it and display the data in a label. However, the view controller is an instance of a subclass of the bundled view controller class.
How do I take the union between an object called on and the object passed in the parameter?I have an interface:
Java Code:
import java.util.Set; /** * An extended Set where additional functionality is added */ public interface NewSet<T> extends Set<T> {
[code]...
Now, the union method requires a NewSet object to be called on. The Union will be performed between the object called on and the object passed in the parameter, which is set.How do I call on a NewSet object in order to take the union between the object called on and the object passed in?Do I just do:
Java Code:
public NewSet<T> union(NewSet<T> set) { NewSet<T> calledOn = new ArrayList<T>(); // ... } mh_sh_highlight_all('java');
I'd like to know how to return a new array, I wrote in a method below the main method. I want to print the array but system.out.print doesn't work for arrays apparently. What structure i should use?
I have to write a method called censor that gets an array of strings from the user as an argument and then returns an array of strings that contains all of the original strings in the same order except those with length of 4. For example if cat, dog, moose, lazy, with was entered, then it would return the exact same thing except for the words with and lazy.
Currently, my code so far just prints [Ljava.lang.String;@38cfdf and im stuck.
import java.util.Scanner; public class censorProgram { public static void main (String args[]){ Scanner input = new Scanner (System.in); System.out.println ("How many words would you like to enter?"); int lineOfText = input.nextInt();
[Code] ....
I have to make new string array in the method and return words without four letters in the main method
I am just trying to test this array, for a locker combination program that involves classes...but the array is printing out the whacky numbers for the location. When I try to call the method in the main, it does not work. How do I call a method that exist within a class into the main method?
public class locker { public static void main(String[] args) { CombinationLock();
package Experimentation; import javax.swing.*; import java.awt.event.*; public class SimpleGUI1B implements ActionListener { JButton button; public static void main(String[] args) { SimpleGUI1B gui = new SimpleGUI1B(); gui.go();
[code]...
This is a program from Head First Java! since main is static it shouldn't be able to call non-static methods because statics do not use any instance variable values but in the above program we're call a non-static method go() how is it possible?
I need to get the string encodedString from the method encode able to be used in the decode method.
Java Code:
public String encode(String plainText) { int prepareString; int shiftChar; String preparedString2 = prepareString(plainText); String encodedString = ""; for(int c = 0 ; c < preparedString2.length();c++)
